2010年12月英语四六级考试阅读专项的练习29

　　Passage 1

　　Using Land Wisely

　　A very important world problem, in fact I am inclined to say it is the most important of all the great world problems which face us at the present timeis the rapidly increasing pressure of population on land and on land resources.

　　It is not so much the actual population of the world but its rate of increase which is important. It works out to be about 1. 6 per cent per annum net increase. In terms of numbers this means something like forty to fifty-five million additional people every year. Canada has a population of twenty million rather less than six months climb in the world population. Take Australia. There are ten million people in Australia. So, it, takes the world less than three months to add to itself a population which peoples that vast country. Let us take our own crowded countryEngland and Wales: forty-five to fifty million peoplejust about a years supply.

　　By this time tomorrow, and every day, there will be added to the earth about 120,000 extra peoplejust about the population of the city of York.

　　I am not talking about birth rate. This is net increase. To give you some idea of birth rate, look at the seconds hand of your watch. Every second three babies are born somewhere in the world. Another baby! Another baby! Another baby! You cannot speak quickly enough to keep pace with the birth rate.

　　This enormous increase of population will create immense problems. By A. D. 2000, unless something desperate happens, there will be as many as 7,000,000,000 people on the surface of this earth! So this is a problem which you are going to see in your lifetime.

　　Why is this enormous increase in population taking place? It is really due to the spread of the knowledge and the practice of what is coming to be called Death Control. You have heard of Birth Control? Death Control is something rather different. Death Control recognizes the work of the doctors and the nurses and the hospitals and the health services in keeping alive people who, a few years ago, would have died of some of the incredibly serious killing diseases, as they used to be. Squalid conditions, which we can remedy by an improved standard of living, caused a lot of disease and dirt. Medical examinations at school catch

　　diseases early and ensure healthier school children. Scientists are at work stamping out malaria and other more deadly diseases. If you are seriously ill there is an ambulance to take you to a modern hospital. Medical care helps to keep people alive longer. We used to think seventy was a good age; now eighty, ninety, it may be, are coming to be recognized as a normal age for human beings. People are living longer because of the Death Control, and fewer children are dying, so the population of the world is shooting up.

　　Imagine the position if you and I and everyone else living on earth shared the surface between us. How much should we have each? It would be just over twelve acresthe sort of size of a small holding. But not all that is useful land which is going to produce food. We can cut out one-fifth of it, for example, as being too cold. That is land which is covered with ice and snowAntarctica and Greenland and the great frozen areas of northern Canada. Then we can cut out another fifth as being too drythe great deserts of the world like the Sahara and the heart of Australia and other areas where there is no known water supply to feed crops and so to produce food. Then we can cut out another fifth as being too mountainous or with too great an elevation above sea level. Then we can cut out another tenth as land which has insufficient soil, probably just rock at the surface. Now, out of the twelve acres only about four are left as suitable for producing food. But not all that is used. It includes land with enough soil and enough rainfall or water, and enough heat which, at present, we are not using, such as, for example, the great Amazon forests and the Congo forest and the grasslands of Africa. How much are we actually using? Only a little over one acre is what is required to support one human being on an average at the present time.

　　Now we come to the next point, and that is, the haves and the have-nots amongst the countries of the world. The standard share per person for the world is a little over twelve acres per head; potentially usable, about four acres; and actually used about 1. 1 acre. We are very often told in Britain to take the United States as an example of what is done or what might be done. Every little American is born into this world with a heritage of the home country, the continental United States, of just about the world averageabout twelve acres. We can estimate that probably some six acres of the total of twelve of the American homeland is cultivable in the sense I have just given you. But the amount actually usedwhat the Americans call improved land in crops and pasture on farmsis three and a half acres. So the Americans have over three times the world average of land on which to produce food for themselves. On that land they produce more food than they actually require, so they have a surplus for export.

　　Now suppose we take the United States great neighbour to the north, Canada. Every Canadian has 140 acres to roam around in. A lot of it is away in the frozen north, but there is still an enormous area of land in Canada waiting to be settled and developed. The official figure is twenty-two acres. The Canadians use at the moment four acres, and they too have a large food surplus available for export.

　　Now turn to our own country. Including land of all sorts, there is just over one acre per head in the United Kingdom of Great Britain and Northern Ireland. That is why we have to be so very careful with it. How much do we actually use? Just over half an acre to produce foodthat is as farm land. The story is much the same if you separate off Northern Ireland and Scotland and just take England and Wales. In this very crowded country, we have only 0. 8 acres per head of land of all sorts to do everything with which we need. That is why we have to think so very carefully of this problem.

　　1. The United States is extravagant in the use of land because Americans produce things that require a lot of land.

　　2. Death control means control of the worlds population.

　　3. Medical care combined with the spread of knowledge has kept he worlds population roaring.

　　4. The United States is a good example of what might be done with cultivable land because the land Americans have is roughly the world average and they are producing more food than they need for themselves.

　　5. The UK boasts of less cultivable land than the U. S. .

　　6. Australia is more populous than Canada.

　　7. The passage gives a general description of the shortage of food supply in comparison with the worlds rapidly increasing population.

　　8. The land suitable for agriculture in the whole world is on little over______per head.

　　9. The populations of America, Australia and England and Wales are examples to show the high______of the world population.

　　10. Antarctica and the Greenland accounts for approximately______of the surface of the earth.

　　I. NG 2. N 3. Y 4. Y 5. Y 6. N 7. N 8. one acre 9. rate of increase 10. 1/5