Text 1: OF WHAT USE?

Today, scientists have a problem when people demand their work to have a "practical use", but they realize that this problem is not new. They recall a story about a student who asked the Greek philosopher Plato of what use was the abstract mathematics he was being taught. Plato at once ordered a slave to give the student a small coin so that he would not think he had gained knowledge for nothing. Then he dismissed the student from the school.
This story of Plato, famous for two thousand years, has not made the matter more evident to most people. Unless the importance of a discovery is clear, most doubts its value.
There is a story about the English scientist Michael Faraday that illustrates this. He was, in this time, a popular lecturer as well as a physicist and chemist. In one of his lectures, he demonstrated the strange behavior of a magnet and a spiral coin of wire which was connected to a galvanometer. A galvanometer records the presence of an electric current.
There was no current in the beginning, but when the magnet was put inside the coil, the galvanometer showed current. While the magnet was moving in or out of the coil, current flowed and the needle on the galvanometer moved.
When the magnet was motionless, the galvanometer showed no current.
At the conclusion of the lecture, one listener approached Faraday and said, "Mr. Faraday, the behavior of the magnet and the coil of wire was interesting, but what possible use can it be?"
And Faraday answered politely, "Sir, of what use is a newborn baby?"
In later years, Faraday made use of his effect to develop electricity cheaply and in quantity, generators make it possible to build the electrified technology that surrounds us. Faraday's demonstration was a newborn baby that grew into a giant.
Astronauts have brought rocks back from the moon. So what? Scientists develop new theories, new mathematical complexities. What for? Of what use are they to the average man and woman?
No one knows right now, any more than Plato or Faraday knew. But you will know, if you live long enough. If not, your children or grandchildren will know. They will be able to answer the question, "Of what use…?"

Adapted from "The Beginning and the End", by Isaac Asinov

Vocabulary

1. Plato: Platon 2. Coin: a piece of metal money 3. To dismiss: to send away forever 4. Lecture: an informative talk 5. Behavior: action, activity 6. Magnet: a piece of metal which attracts iron 7. Coil: "rouleau" 8. Needle: "aiguille"

Questions

Text 2: Man: a most adaptable animal

There are many areas in this world where not every kind of organism can live. For example, there are no trees in the Arctic regions, the land of the polar bear. Of course, there are no polar bears in the lush vegetation of the tropics. Man, on the other hand, lives successfully in both of these environments. In fact, he has found ways to survive anywhere on Earth. He has learned to alter this environment to suit him. If he needs large amounts of water for big cities, he builds dams. If he needs water for farming the desert, he builds irrigation canals. Neither the highest mountain nor the deepest rivers stop the movement of man. How does he overcome such obstacles?
Medicines and insecticides help man destroy organisms that he considers a threat of his food supply. He has learned to survive in unfavourable or hostile environment. For example, he tunnels underground, works in the frigid Polar Regions, and explores at various depths in the oceans. Also he can live at high altitudes where no other organism can exist. If a man moves from sea level to 5,000 feet above sea level, where the air has less oxygen, certain functional adaptations will enable him to survive in the "thin" air. His breathing will increase. The number of his red blood cells will increase, and his heart will beat faster, causing the red blood cells to circulate more quickly. Most other animals can adjust to this slight change in environment. Suppose, however, that an animal is carried to a height of 25,000 feet. Will it survive? It probably would not be able to adjust to the reduced air pressure and to the lack of oxygen at this altitude. Man is exception, however, because he has survived at this altitude for extended periods of time. In fact, you may have done so yourself. Have you ever flown in an airplane? Jet airplanes fly above 25,000 feet. How do passengers survive? Do they adapt to this almost-oxygen-free environment? Of course not. The plane cabins are pressurized so that the environment resembles that at a lower altitude.
Man has this selective advantage over the plants and other animals: if he cannot adapt to a changing environment, he adapts the environment. "A question of survival", Life.

Text 3: Magnets

1 A magnet is a substance which attracts certain other substances. 2 A substance which is attracted by a magnet can itself be made into a magnet.
3Generally speaking, there are three substances which are attracted by a magnet: iron, cobalt and nickel. 4Substances which are attracted by a magnet are known as magnetic substances, and those which are not are referred to as non-magnetic substances. 5Iron, cobalt and nickel are magnetic substances. 6They are attracted by magnets and they can themselves be magnetized.
7Mixtures of metals, or alloys, which contain a magnetic substance generally also have magnetic properties. 8Some alloys containing none of the above metals, however, are also magnetic. 9Certains alloys containing manganese, aluminium and copper belong to this class. 10They are magnetic, even though they contain no metal which is itself magnetic.
11A magnet will attract a magnetic substance like iron. 12Not all parts of a magnet, however, have equal attractive force. 13If a bar magnet is placed in iron filings, most of the filings will stick to the ends of the magnet, and very few will adhere to the central part. 14The force of attraction, or magnetic force, is concentrated near the ends of the magnet. 15These areas are known as the poles.
16A magnet sets in a definite direction when freely suspended. 17If a bar magnet is suspended by a thread and allowed to move freely, it will come to rest with one pole pointing towards the south. 18The pole pointing towards the north is called the north-seeking, or north, pole; and that which points towards the south the south-seeking, or south, pole.
19If the north poles of two freely suspended magnets are brought into proximity, so that they are close together, the ends of the two magnets will swing away from each other. 20If on the other hand the north pole of one magnet is brought close to the south pole of the other, the two ends will attract each other. 21A north pole will attract a south pole and repel another north pole, and be attracted by a south pole and repelled by another north pole. 22Like* poles repel one another and unlike** poles attract one another.

From "English for Scientific Classes"
* similar - ** different

QUESTIONS
I/ True or not true?
a) A magnet attracts other substances.
b) Iron, cobalt and nickel are the three substances which are attracted by a magnet.
c) Cobalt can be made into a magnet.
d) Alloys which contain a magnetic substance are always magnetic.
e) Manganese is a non-magnetic substance.
f) Alloys containing aluminium are magnetic.
g) The central part of a bar magnet has no magnetic force.
h) Most of the magnetic force in a magnet is near the poles.
i) A south pole will attract a north pole.
j) A north pole and a south pole are like poles.
k) Two magnets freely suspended will swing away from each other when they are brought close together.

II/ Contextual reference

1. In sentence 8, the above metals refers to: (a) Iron, cobalt and nickel. (b) Alloys.
2. In sentence 9, this class refers to: (a) The class of alloys which contain a magnetic substance. (b) The class of alloys which contain no iron, cobalt or nickel but are magnetic. (c) The class of alloys which contain manganese, aluminium and copper.
3. In sentence 10, they refers to: (a) Manganese, aluminium and copper. (b) Certain alloys containing manganese, aluminium and copper.
4. In sentence 15, these areas refers to: (a) The force of attraction (b) The ends of the magnet.
5. In sentence 19, they refers to: (a) The north poles. (b) The two magnets.

III/ Paragraph writing
Stage 1: sentence building

1. MAGNETIZED/ SO THAT/ UPRIGHT/ WITH/ PROTRUDING/ , AND/ HORIZONTALLY  

Place a knitting needle in a cork/ it will float in a trough of water/ its north pole will just protrude out of the cork/ support a bar magnet above the water

2. THAT/; / (1797-1867)/ TO/ OF/ WHAT/ SURROUNDING   

it is important to realize this/ lines of force have no objective existence/ they were suggested by Michael Faraday/ they give a mental picture/ something is happening in the space/ the space surrounds a magnet

3. FLOATING/ WITH ITS/ AND/ IT  

put the needle near the magnet/ the north pole of the needle will be near the north pole of the magnet/ release the needle

4. THE EXISTENCE OF/ BY A SIMPLE EXPERIMENT  

 lines of force exist/ this may be demonstrated

5. TO THE SOUTH POLE OF THE MAGNET  

the needle will travel along a curved path

6. TO/ DIFFERENT/ , AND/SO  

a diagram can be drawn/ the diagram will represent the paths/ the paths are traced out by the needle/ the lines are drawn/ the lines indicate lines of magnetic force

7. ; THAT IS, / TEND TO/ WHICH  

the forces act along definite lines/ magnetic poles will be driven along certain lines/ these lines are called lines of force

8. AS/ AN INDEPENDENT/ WHEN/ IT/ FREE TO MOVE   

we can define a line of magnetic force/ a line of magnetic force is the path of a needle/ the path is traced out by a north pole/ the north pole is under the influence of a magnet

9. THE/ ROUND A MAGNET/ CALLED  

this area is a magnetic field

10. IF/ WITH/ , / ALWAYS/ ,BUT  

the experiment is repeated/ the needle will be in different starting positions/ the starting positions will be near the north pole of the magnet/ the needle will travel to the south pole/ the needle will travel along different paths

Stage 2: Paragraph building

Text 4

"The fact is - and I challenge anyone to deny it - we are busily engaged in weakening the human race. For years the natural balance of nature kept populations in check. When the birth rate became too great there were famines to offset it. It's the elimination of the weak.

When there was a plague or an epidemic it was the weak who were wiped out and the strong survived. Other illnesses did the same thing: there was a level maintained - nature's level. And because of this, it was the strong who perpetuated themselves. They were the ones who sired the next generation.

We are moving towards degeneracy, at least in the Western world. We're preserving the cripples, the weaklings and the disease-ridden. We are accumulating burdens on society, non-producers - the unfit, unable to contribute anything to the common good. Tell me - what purpose does a sanatorium or a house for uncurables serve?

I tell you, medicine today is preserving people who should be allowed to die. But we're helping yhem to live, then letting them spawn and multiply, passing along their useleness to their children and their children's children."

"You say that illness and disease are nature's levellers. But many of these things haven't come to us in the natural course of nature. They are the result of man's own environment, conditions he's created himself. Bad sanitation, lack of hygiene, slums, air pollution - those are not natural things, they're man's creation."

"They are part of evolution and evolution is part of nature. It all adds to the balancing process."

"If you are right, then medicine is a part of the balancing process too. Because medicine is a part of evolution. Because every change of environment that man has had produced its problems for medicine to face and to try to solve. We never solve them entirely. Medicine is lways a little behind, and as fast as we meet one problem there's a new one appearing ahead."

VOCABULARY
Weaken: make weak Offset: counterbalance Sire: procreate Cripple: disabled, having a handicap Sanatorium: hospital Spawn: make progeny, descendants

QUESTIONS

Text 5: Xenotransplantation's Paradox

Transplantation surgeons work miracles. They take organs from one body and integrate them into another, granting the lucky recipient a longer, better life. Sadly, every year thousands of other people are less fortunate, dying while they wait for suitable organs to be found. The terrible constraint on organ transplantation is that every life extended depends on the death of someone young enough and healthy enough to have organs worth transplanting. Such donors are few. The waiting lists are long, and getting longer.

Freedom from this constraint is the dream of every surgeon. So far attempts to make artificial organs have been disappointing: nature is hard to mimic. Hence the renewed interest in trying to use organs from animals.

The ethics of xenotransplantation are relatively unworrying. People already kill pigs both for food and for sport; killing them to save a human life seems, if anything, easier to justify. However, the science of xenotransplantation is much less straightforward.

Import an organ from one animal to another and you may bring with it any number of infectious diseases. That is much well known. Many diseases that could harm humans may be both undetectable and harmless in their natural hosts. Diseases that have been dormant for years may suddenly become active if they find themselves in a new environment, such as a human recipient's body. After that, they may start to infect other people. This risk should not be underestimated. The DNA of every organism carries within it hundreds of ghosts of infections past. Although most of such "retroviruses" gradually lose their infectious powers, some retain their ability to leap out of the host DNA - often much later.

Of course it is possible that none of the retroviruses will be harmful to humans; possible too that scientists will eventually isolate all prospective troublemakers. But at a time when thousands of British cattle are being slaughtered because of the suspicion that they have a disease that may be transmissible to humans, it seems a reckless gamble to take.

Adapted from The Economist, December 21st, 1996, p.16.

VOCABULARY:

DNA: Deoxyribonucleic acid; the acid that carries genetic information in a cell.
To leap out: surgir, apparaitre
To slaughter: to massacre, to kill
A reckless gamble: un jeu trop ose.

GUIDED COMMENTARY

1) According to the text, what does xenotransplantation consist in?
2) What made surgeons consider xenotransplantation as a possible way to prolong life?
3) Why is it xenotransplantation risky?
4) Would you accept the organs of other species if this could save your life? Why or why not?

Trees are useful to man in three very important ways: they provide him with wood and other products ; they give him shade ; and they help to prevent drought and floods.
Unfortunately, in many parts of the world, man has not realised that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers.
This doe not only mean that our sons and grand sons have fewer trees. The results are even more serious: for where there are trees their roots break the soil up - allowing the rain to sink in - and also bind the soil, thus preventing its being washed away easily; but where there are no trees, the rain falls on hard ground and flows away on the surface, causing floods and carrying with it the rich top-soil, in which crops grow so well. When all the topsoil is gone, nothing remains but worthless desert.
Even where a government realises the importance of a plentiful supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food with; and he can earn money by making charcoal or selling wood to the townsman. He is usually too lazy or too careless to plant and look after new trees. So, unless the government has a good system of control, or can educate the people, the forests slowly disappear.
Two thousand years ago a rich and powerful country cut down its trees to build warships, with which to gain itself an empire but without its trees, its soil became hard and poor. When the empire fell to pieces, the country found itself faced with floods and starvation.

Vocabulary
To provide with: fournir shade: ombre
Drought: (derived from dry) floods: inondations
To sink: s'infiltrer

COMPREHENSION

Text 7: The three states of matter

Text 8: Society's right to kill

Men of good will recognize it to be incontestably true that we are our brother's keepers, and one man cannot be abandoned and sacrificed upon the altar of society's sometimes unreasonable demands without disturbing all mankind. There was a time when society thought that criminals should be beheaded, burned, boiled or buried alive; when men were strangled, stoned or starved to death; when they were forced to drink poison, crucified, or drowned; when they were eaten alive by snakes or lions, all of this in the name of justice and all because it was "the law of the state".
As odious and savage as these practices sound us today, let's face the fact that electrocution will be listed as another barbarous, cruel uncivilized punishment. During the reign of Queen Elizabeth I, 19,000 Englishmen were executed but the crime rate continued to rise.
During the reign of Henry VIII, 72,000 Englishmen were executed; this however did not seem to deter Englishmen from committing crimes.
Peter I, tsar of Russia, in 1728 put to death 8,000 Russians, because they were wearing beards, and yet today we can hardly think of a Russian without a beard.
To me, one of the most compelling arguments against capital punishment is the possibility of mistake. So many times have the innocent been mistakenly convicted or wrongly convicted. Now I am going to give you a full descrption of how the state kills a man: at about 5:30 in the afternoon of the eve of the execution, the prisoner is shaved, bathed. He must be clean so that it is unecessary to bathe his body after the electrocution.
Then they give him a new shirt and a new pair of pants, without a belt and shoes without laces.
Next a priest of his choice visits him to offer whatever words of assurance. Then the condemned man is given an opportunity to eat some good meal of his choice. Then his family is permitted to visit him until midnight. And in the morning he is placed in the electric chair and killed.

Adapted from Joe W. Henry, Jr.

Vocabulary

To behead: to cut the head
To deter: to prevent
The eve: the day before
Altar: autel

Comprehension

Text 9: The manipulation of genetic traits    (N°9-N°21 sent by Emile KAHOUN, Lycee Yadega, nekemile@hotmail.com) 

Today , much work in genetic engineering concerns the future of all mankind. Genetic scientists will soon be able to create 'ideal' human beings. However there is much disagreement about what a 'perfect' genetic inheritance is. ....
Three traditional techniques of controlled breeding can be described. One is hybridisation , which means crossing two different kinds of plants or animals. The result is a hybrid. Crossing a male donkey and a female horse , for example produces a mule. A mule is a hybrid animal. A second breeding technique is the creation of mutations. In this method , scientists use changes in cell structure to alter plants and animals. For instance , different types of radiation and chemicals are applied to the penicillin to derive the drug penicillin.
A third technique for breeding improved animals is the selection of most desirable parents for producing offspring. This is often combined with artificial insemination . In this method , semen is collected from a top quality male animal .The semen is then placed in the reproductive organs of females. One way this method is used is in the producing of fast ,beautiful horse and large and meaty cattle.
The genetic selection of human beings is also being experimented . Many medical institutes in the U.S.A and elsewhere have sperm banks .These are laboratories or clinics where human sperm is collected and kept alive. It's used for artificial insemination of women. In some cases , the sperm banks collect sperm from individuals who are especially intelligent , such as Nobel Prize winners. Some scientists think that the children resulting from this donated sperm may inherit the high intelligence of their fathers. The mothers are carefully chosen also.
A study by Lewis M . Terman in the 1920's suggests that the genetic theory behind sperm banks has some truth in it. Terman's study indicates that the parents with high intelligence also have children with high intelligence. This has convinced some people that 'superior' genes exist. Therefore , some people think that sperm banks can help mankind avoid dysgenic. Dysgenic is evolution toward a lower rather than a higher level.
Many people however do not approve the genetic selection of humans. They say it is similar to the ideas of Hitler and the Nazis in trying to create ' super race'. They wonder what the definition of a ' perfect human' is. They question the concept that one individual has the right to control the destiny of others.

Drobni c , K. et al. Reading and writing  the English of Technology .

QUESTIONS

Text 10: The Global threat of Drug Abuse
The international drug abuse situation is grave. Global cultivation and production of opium coca cannabis continue to expand.
The supply of the products made from these crops far exceeds the demand for them , but the demand is also rising , particularly in the producing and trafficking countries. These countries once immune from the effect of illicit drugs , now have growing addict and abusing populations. Like western Europe and the United State , what they are exploring to fight back , realising that illicit drugs pose a threat not only to the health of the people , but also to domestic order and national security.
Drug production and trafficking are a big business: the product is lucrative , needs little advertising , and keeps the customer coming back for more. The criminal organisations running those businesses are skilful and ruthless . They battle against all organised efforts to curtail their activities. When a government mounts an intensive eradication campaign , traffickers often counter by planting larger crops , moving their fields to more remote areas , or mounting misinformation campaigns to convince the population that the government is harming its citizens by eradicating illicit drug crops. When processing laboratories are destroyed , the traffickers build new ones or design mobile fabs that can be moved quickly. They counter law enforcement efforts with corruption and violence , bribing or killing those whose activities threaten their work.
International boundaries have no meaning for drug traffickers . If one Government is able to disrupt their activities significantly , they simply move to another country.

Notes
Threat: menace ; addict: personne addonnee a ; ruthless: impitoyable , insensible.
Curtail: racourcir , abreger.

TEXT 11: The Sources of Energy
Fire, water, wind and oil are important sources of energy. They provide electricity, cook food, and run the machines which manufacture what people need. Because the world's population is increasing, and because industry and technology are growing, additional supplies of energy sources, such as oil and gas, are hard to get and expensive, however. Others are not yet efficient. There fore, the development of alternate sources of energy is an important goal of today's scientists and technologists. This reading tells about three alternate sources solar energy, geothermal energy, and coal.
Solar energy comes from the suns heat. Large panels are used to collect the heat brought to the earth by the rays of the sun. The heat is then stored in thermal mass. It can be used to heat water and homes and to generate turning to coal as a source of energy. The Soviet Union, the United States, and China all have large coal deposits.
Although solar energy can be changed into heat , light and mechanical power and chemical energy , there are problems in using it effectively . One problem with solar energy is that many places often have dark and cloudy weather. How can power from the sun be collected in such places ? . One answer is the photovoltaic cell ( a solar battery or solar cell ) , which store energy for use when there are no direct rays from the sun. Another problem is that , up to now , solar cells cannot provide energy as cheaply and efficiently as other devices can. For this problem there is at present no answer.
As oil becomes expensive , more and more countries are turning to coal as a source of energy. The Soviet Union , the USA and China , all have large coal deposits. The main difficulty with burning coal is that it pollutes the air, It may even be the source of "acid rain", which is rain containing harmful chemicals.

K. Drobnic S. Abrams and M. Morray, Reading and Writing the English of Technology.

VOCABULARY
efficient : efficace
ray : rayon
dark : obscur, sombre
cloudy : nuageux
coal : charbon.
QUESTIONS

Text 12: DOWSING

Most happenings can be explained through Science. In fact , in science there are laws that describe how things happen and why. The law of gravity for example: everything that goes up must come down . There are no exceptions except for rockets that leave the Earth's gravity.
These natural laws can explain nearly everything that happens on Earth , but not quite all things. Some happenings seem still beyond science.
An example of a practice that science cannot explain is one of the oldest ways of finding well water , finding a good place to dig for water. . The person is usually , but not always , a man over the age of thirty .He holds the two ends of a V-shaped stick out in front of himself. In the hands of a person who has the power or ability to find water , the stick will shake and point down , showing a good point to dig for a well.
Is there a scientific explanation for this procedure of finding water? No , there is not yet.
Dowsing , as this process is called , is still beyond the ability of science to explain. Because people cannot explain it , they do not trust it. "water witching" is the name that people have given to dowsing because they think it must be evil.
Dowsing is actually very all . They are a few pictures of ancient Romans , Greeks , and Incas holding V-shaped sticks. Where they looking for water ?
The religious leader Moses needed water for his people while they were crossing the desert . Moses hit a rock with a stick and found water for his people. Did he, use a dowsing stick ? We do not know the answers to thee questions . We must look for written records that are more clear . In any cases , dowsing is an old arts that people do not understand but they still use because it works.

NOTES:
Laws: loi ; a stick :un baton ; a V-shaped stick: un baton en forme de V; a rocket: un fusee ; gravity : pesanteur.

Text 13: HEALTH
Until the twentieth century some people confused being able to stay in a vertical position , with being in good health .As long as one could stand and walk , he was not ill. Everything will be alright as soon as he is on his feet . Today , a wildly accepted definition developed by the World Health Organization says that: "health is a state of complete physical , mental and social well-being , not simply the absence of disease or infirmity. "
Good health is not often seen as a goal in itself ; it 's a means to attain goals (1) and a necessary condition for success in almost everything. Health is a changing and dynamic quality of life . There are many interrelated factors that play a vital part in the development and maintenance of sound health. Many of these factors are apparent : heredity ; nutrition ; rest ; sleep ; exercise ; fatigue and accidents. Others are less apparent but significant. They include excesses ; noise….
Some cultures kept early beliefs regarding health and sickness. Supernaturalism remained dominant , with religion playing a central role . Demons , spirits , and numerous gods (2) continued to be thought the source of ill-health and spells (3) and sacrifices were done to appease them.
Some very practical and scientific measures made notable contribution to heal and medicine such as :large scale vaccination programs , the introduction of insecticides , the advancement in chemotherapy (4) for example drugs , antibiotics , vitamins and other important discovering in nutrition , the significant advances in surgical procedures and techniques , including organ transplantation.
Education and persuasion are the keys to public health. They are directed towards programs of education , prevention , and treatment of disease and infirmities.

Foundation of Health Science (Adapted by B . Osbord Henkel)

1) goal : objective ; (2) gods : divinities ; (3) spells: "des sorts" ; (4) chemotherapy: use of chemical material as medicine.

QUESTIONS

1)What is the illusion as far as health is concerned. (5 lines) 2marks.
2) Is health the absence of illness ? Justify your answer. (6 lines) 2marks.
3) What is the people's dogmatic view of ill-health. ? (5lines) 3marks.
1) Has health known any notable evolution nowadays? Why? (5lines) 3marks.

GRAMMAR ( 5marks)

Use the correct tense of the verb.
1) It(to rain) now
2) Look! The dog (to play) with the cat.
3) Franck (to drink ) tea everyday.
4) You (to wash) the car tomorrow;
5) Bob (to buy) two books last week
.
TRANSLATE INTO ENGLISH.(5marks)

Text 14: THE WORLD FOOD CRISIS

People all over the world are concerned about the problem of hunger. Many individuals and religions , national and international organizations have worked to eliminate this terrible problem . However , their efforts have met with only limited success . In Asia and Africa for example , millions of people still, fight a constant battle against starvation . All of us agree that this crisis must be solved quickly and effectively . However the causes and solutions of the hunger problem are varied and complicated .
On the one hand , agricultural production has always depended on weather conditions . Even in today's modern world where great scientific advances are seen everywhere , humanity has not yet learned how to control or even influence the weather . The amount of rainfall is one very important factor that can cause agriculture to succeed or fail. Some countries have problems with floods , others suffer from the opposite condition: long periods of drought that leave land dry , hard and unproductive .
On the other hand , to increase food production , technology is needed , and the high cost of this technology is another problem of agriculture . Farm machinery is not cheap. Some machines cost thousands of dollars . The high price of oil also makes increasing agricultural production more expensive , because oil is needed to operate machines to produce and transport food and to produce most of the fertilizers that can be used to improve the quality of soils.
A third factor that causes the world wide food crisis is the extremely rapid rate of population increase . World population continues to increase at a nearly 100 million people a year. As a result , it is impossible for the agricultural production to keep up with the population growth. . It has been predicted that if the agricultural output is not greatly increased , and the birth rate is not dramatically decreased , the situation will be more disastrous in the near future .

Notes:
Crisis : crises ; hunger/starvation: faim ;

Today , much work in genetic engineering concerns the future of all mankind. Genetic scientists will soon be able to create ‘ideal’ human beings. However there is much disagreement about what a ‘perfect’ genetic inheritance is. ....

Three traditional techniques of controlled breeding can be described. One is hybridisation , which means crossing two different kinds of plants or animals. The result is a hybrid. Crossing a male donkey and a female horse , for example produces a mule. A mule is a hybrid animal. A second breeding technique is the creation of mutations. In this method , scientists use changes in cell structure to alter plants and animals. For instance , different types of radiation and chemicals are applied to the penicillin to derive the drug penicillin.

A third technique for breeding improved animals is the selection of most desirable parents for producing offspring. This is often combined with artificial insemination . In this method , semen is collected from a top quality male animal .The semen is then placed in the reproductive organs of females. One way this method is used is in the producing of fast ,beautiful horse and large and meaty cattle.

The genetic selection of human beings is also being experimented . Many medical institutes in the U.S.A and elsewhere have sperm banks .These are laboratories or clinics where human sperm is collected and kept alive. It’s used for artificial insemination of women. In some cases , the sperm banks collect sperm from individuals who are especially intelligent , such as Nobel Prize winners. Some scientists think that the children resulting from this donated sperm may inherit the high intelligence of their fathers. The mothers are carefully chosen also.

A study by Lewis M . Terman in the 1920’s suggests that the genetic theory behind sperm banks has some truth in it. Terman’s study indicates that the parents with high intelligence also have children with high intelligence. This has convinced some people that ‘superior’ genes exist. Therefore , some people think that sperm banks can help mankind avoid dysgenic. Dysgenic is evolution toward a lower rather than a higher level.

Many people however do not approve the genetic selection of humans. They say it is similar to the ideas of Hitler and the Nazis in trying to create ‘ super race’. They wonder what the definition of a ‘ perfect human’ is. They question the concept that one individual has the right to control the destiny of others.

Drobnic , K. et al. Reading and writing the English of Technology.

QUESTIONS

Bionics is a fusion of biology and electronics. Biologists and electronic engineers put their energy together to design devices that resemble and can replace body organs. The term first came into use in the 1960s but bionic devices have existed for ages. Modern bionics is specially interested in devices that are substitutes for body organs lost through accidents or that function badly due to infection or genetic disorders.

In 1934 , the first artificial heart-and-lung machine started operating. As a bionic device , it was used as a temporary substitute while the patient was in surgery or under short-term treatment.

Another bionic device was the artificial heart valve. This is a synthetic replacement for malfunctioning heart valves. The electronic "pacemaker" was the next bionic achievement. It is a gadget implanted in the body to facilitate the beating of an ailing heart.

In 1954, the first open heart surgery was carried out in Minnesota , USA , by Dr C.W.Lillehei. The patient was operated upon while blood was supplied to him directly from a donor.

In 1983 , a team of doctors at the un university of Utah Medical Centre , USA, replaced the diseased heart of Dr Barney Clark with an mechanical one. He amazingly managed to survive for 112 days after the operation.

Recent progress in electronics has enabled scientists to develop an artificial eye in which signals are transmitted into light pattems that are sent into nerve receptors in the patient. Though a young science , the future of bionics is both promising and exciting. Definitely , existing bionic devices will be perfected to smaller , faster and more efficient ones. The success in replacing the Dr B. Clark's heart will trigger the fabrication of other devices like bionic livers , stomachs , lungs and kidneys.

Then hopefully , patients who, for religious , ethical , or medical reasons do not or cannot receive these vital organs from other animals or humans , might be better served.

From "Applied Science ", Short reading in Sciences by Dean Curry , 1988.

Vocabulary

To trigger: to start.

 QUESTIONS

In the wake of last September's flood disaster in Bangladesh, which left up to a third of the population homeless, scientists are warning that continued destruction of the world's forest will trigger(1) an increasing number of similar catastrophic floods. The destruction of vast forest areas of Nepal, Northern India, and Bangladesh has been a major factor in the floods that have plagued Bangladesh in recent years. Forests help prevent flooding by holding the soil in place and absorbing much of the rain. Forests also supply much of the oxygen essential to life on earth.

Tropical forests, the most important surviving woodlands, contain about two thirds of all plant animal species. At the present rate of deforestation, an estimated 15 percent of all species could disappear within the next two decades.

The area of tropical forest denuded between 1955 and 1980 is equal to that cut down during the preceding two centuries. During this 25-year period in Africa an estimated 3.6 million hectares of tropical woodlands were cleared annually for timber (2) and agricultural use. In tropical Asia, some 1.8 million hectares were cleared between 1976 and 1980. The Himalayan covering Northern India, Nepal, and Bangladesh- had lost 40 percent of its forest a by 1980. And high rates of deforestation have been recorded throughout Latin America - particularly in Haïti, Brazil, and Central America. In Haïti over 20 percent of the forest cover has been stripped, and deforestation continues.

The deforestation problem is particularly acute in developing countries. Until the late 1960's developing nations viewed their forests mainly as a source of income to be used in the manufacturing and government sectors. As forests were cleared, soil erosion and salinization have increased. Coastal habitats have been destroyed, severely affecting local fish populations. Much of the deforested land has been marginal -not suited to annual crop production - but has been brought under cultivation with lasting harm to the local environment.

The U.S government, concerned about the rapid disappearance of the world's forests, has made forest conservation a major goal of its foreign assistance programs. In 1987, the Agency for international Development applied over 56 million dollars to 146 forestry projects in 46 developing nations.

It took nature ages to produce the great forests of the world. It takes man only moments to decimate them. Preserving what remains of this precious natural heritage should be among the highest priorities of all governments and all people.

Excerpt from Voice n°31 (February / March 1989 ).

VOCABULARY

(1) to trigger : to bring about a chain of events

(2) timber : wood for building.

QUESTIONS:

1) What, in your won words, are the effects of deforestation on floods ? (2marks )

2) How is the survival of species threatened by deforestation ? ( 3 marks )

3) Referring to the text, what do you learn about the causes of deforestation in developing countries ? Are there any other reason you know of ? Justify your answer ( 4 marks )

4) "It took nature ages to produce the great forests of he world. It takes man only moments to decimate them". Explain and comment. ( 5 marks )

Polluted air is found in most cities. It is caused by burning coal, oil, and natural gas. Polluted air is not only unpleasant, it is harmful. Polluted air can cause respiratory infections, lung cancer, allergies, and other diseases. Polluted air also harms plants and reduces crop yields.

Motor vehicles are a major source of air pollution in the United States, Carbon monoxide, hydrocarbons, and nitrogen oxides are the main pollutants in auto exhaust. They are the result of burning gasoline in a car's engine.

Carbon monoxide is a colourless, odorless gas. It is poisonous. Carbon monoxide gas in auto exhaust can cause suffocation. Hydrocarbons and nitrogen oxides are gases which cause photochemical smog. Photochemical smog gases in the presence of sunlight. One of the products of the change is ozone gas. Ozone irritates the linings of the nose and throat. It makes one's eyes water and sting. Many cities have photochemical smog. Sometimes no wind blows and the air is still for a long time. When this occurs, photochemical smog can build up quickly dangerous amounts. The smog can cause sickness and death.

The design of the gasoline engine has been changed somewhat to reduce air pollution from exhaust. Some governments require that automobile engines meet certain pollution standards. To meet these standards, antipollution devices are added to the engines. These help to reduce the harmful gases released in auto exhaust.

Some gasoline contains lead. When lead is present in gasoline, it becomes a pollutant in exhaust. Lead pollutants in the air can be harmful to people, other animals, and plants. Lead poisoning can cause permanent damage to the brain and nervous system. New cars are designed to use low-lead or lead-free gasoline.

Many scientists believe that the gasoline engine should be replaced. Turbine engines use gasoline fuel more efficiently. Engines which use natural gas or hydrogen for fuel produce few pollutants. Automobiles operated by rechargeable electric batteries produce few pollutants.

Sulfur dioxide and particulates are major air pollutants. They are produced by the burning of fuels in homes and industries. Sulfur dioxide is a colourless gas with a bad odor. Sulfur dioxide can cause respiratory problems and it is poisonous. Some of the sulfur dioxide in polluted air combines with water vapour to form an acid. The acid harms plants corrodes metal, and damages stone. Particulates are particles of all sizes that emitted into the air. Ash, dust, and smoke are particulates. They contribute to smog. Particulates vary in their chemical structure. Some cause respiratory ailments.

Pollution by sulfur dioxide and particulates can be controlled. Sulfur dioxide pollutants can be reduced by burning kinds of oil and coal which do not contain much sulfur. Also, the sulfur can be removed before the fuels are burned. Particulates can be removed by filters placed in smokestacks. Most large cities have laws which regulate the release of air pollutants by industries. However, the laws are not always enforced.

QUESTION

1) What is air pollution ? ( 2 marks)

2) How does air get polluted referring to the text ( 4 marks )

3) It is true that air pollution has no consequences (justify your answer referring to the text) (6marks)

Chemicals have long been part of everyday existence , from agriculture and industry to prevention and control of diseases. While so often of inestimable benefit , they can also , if misused , damage both health and environment.

Exposure to chemicals varies largely , from high concentration of short duration affecting groups of workers to entire populations subjected to continued low levels. The cumulative effects depends on the degree and duration of this exposure and the kind of substances causing it. People react differently. Some are markedly less resistant than others , such as pregnant women , infants and young children , the elderly , the malnourished and the chronically ill.

While awareness of such treats is steadily spreading, politicians , administrators and managers remain ,for the most part, far from adequately informed. The same applies , even more so to the public at large in many countries , particularly where toxic chemicals in agriculture are concerned. Major chemical disorders , filing the headlines have served top further this awareness. Over the past two decades , hundreds of accidental discharges at chemical plants and spills due to accidents in transport have polluted the immediate surroundings with sometimes catastrophic effects on local populations. More and more of these are occurring in developing countries , ill equipped to cope with them. Inadvertent discharges and irresponsible , sometimes totally unscrupulous dumping of hazardous waste is not the sole problem. Up to half a million people die annually in developing countries through accidental poisoning by chemicals , pesticides in particular , and natural toxins.

Through international efforts, countries have to be helped in acquiring essential knowledge of what the harm chemicals can do when incorrectly applied. They have to be advised , also, on drawing up laws and regulations for handling , use and disposal , as well as enforcement, inspection measure and accident contingencies plans.

Adapted from Our Planet, Our Health, By The World Health Organisation.

GUIDED COMMENTARY.

1) What positive role do chemicals play in man's life according to the text? (4marks)

2) Explain in your own words the dangers related to chemicals for man and his environment. (4marks).

3) How did people become aware of the harmful effects of chemicals? (4marks)

Our bodies are wonderfully deft at maintaining balance. When the temperature jumps, we sweat to cool down. When our blood pressure falls, our heart pound to compensate. As it turns out, though, our natural state is not a steady one. Researchers are finding that everything from blood to brain function varies rhythmically with the cycle of sun , moon and seasons. And understanding them is giving new strategies for avoiding such common killers as heart disease and cancer. Only one doctor in 20 is well versed in the growing field of "chronotherapeutics", the strategic use of time (chrono) in medicine. "The field is exploding", says Michael Smolensky, the university of Texas psychologist who heads Houston's Hermann Centre for Chronobiology and Chronotherapeutics.

In medical school, most doctors learn that people with chronic conditions should take their medicine at steady rates. For example, asthmatics are most likely to suffer during the night , when mucus production increases, airways narrow and inflammatory cells work overtime. Yet most patients strive to keep a constant level of medicine in their body day and night, whether by puffing on an inhaler four times a day or taking a pill each morning and evening. In recent studies, researchers have found that a large midafternoon dose of a steroid or broncodilator can be as safe as several small doses , and better for avoiding nighttime attacks.

In 1989, Dr William Houshesky of Albany's Stratton VA Medical Centre analysed the records of 41 women who'd undergone surgery for breast cancer and found that those operated on midway through the menstrual cycle enjoyed better 10-year survival rates than those treated at other times of the month. His colleagues laughed at the time, but nine studies involving 2,300 women have turned up the same result. Those studies suggest that midcycle breast surgery may bring a 30 percent survival advantage. If so, it could prevent 15,000 deaths a year in the United States alone. And unlike most new treatments , this one would cost no more than what it replaced. Time, after all, is free.

By Geoffrey Cowley, Newsweek, March 11, 1986 (adapted)

Deft: adroit

Steady: regular, constant.

Versed in: experienced in

To narrow: retrecir

To strive: to make great efforts.

GUIDED COMMENTARY

1) According to the text, how do the cycles of sun, moon and seasons influence our health? (03 marks).

2) Give the definition of chronotherapeutics.(03marks)

3) Referring to the text, when can asthma treatment be more effective? (02 marks)

4) Referring to the results of studies in the text, what is the most suitable time for performing breast-cancer surgery and why? (04marks)

About a billion people worldwide are at risk of iodine deficiency, a trace element found in salt water fish, seaweed and in non-leached soils. Iodine is essential for brain development in the foetus and in children and for the thyroid gland to regulate the body's metabolism.

Those who obtain too little iodine may suffer mental retardation, stunted growth and goiter, or enlargement of the thyroid gland. Iodine deficiency also causes many less visible but equally insidious health problems, including a high rate of infant mortality, low birth weight and learning disabilities. Although the most critical areas of deficiency are in Central Africa and Southern Asia, the problem is not limited to landlocked areas or the developing world. Some coastal regions also show deficiencies, and several European countries that do not have iodized salt programs have a high incidence of goiter.

At the urging of the World Health Organization, the United Nations Children's Fund and the International Council for the control of Iodine Deficiency Disorders, the UN's World Summit for children pledged in 1990 to eliminate iodine deficiency in the world by the year 2000.With that in mind, a team of scientists headed by Dr Réné Tonglet of the Free University of Brussels, conducted a year-long study in the Kivu region of Zaire, where iodine deficiency is endemic. The results of their research , recently published in the New England Journal of Medicine , offer hope that a relatively simple and cheap means of alleviating the problem in high risk areas may be at hand. The scientists found that a single tiny dose-one tenth of a millilitre-of iodised vegetable oil, given orally, can prevent iodine deficiency for up to a year in the people they tested.

Time International, February17, 1992, p.49

Seaweed: algue

Unleached: is opposite to leached; to leach: filtrer.

Stunted: chetif, rabougri.

To pledge: prendre l'engagemnet.

To alleviate. To make less intense or severe.

Deficiency: insuffisance, defaut.

GUIDED COMMENTARY

1) State the nature and the function of iodine with reference to the text. (03marks)

2) What generally happens in case of lack of iodine? (04marks)

3) Where does iodine deficiency manifest itself? (04marks)

4) What are the strategies of fight undertaken by International Services to eliminate iodine deficiency in the World? (05marks)