[A] strict traffic regulations are badly needed

[B] drivers should apply road politeness properly

[C] rude drivers should be punished

[D] drivers should avoid traffic jams

Text 2

In the atmosphere, carbon dioxide acts rather like a one-way mirror -- the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping.

According to a weather expert’s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several metres and severely flooding coastal cities. Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of earth’s chief food-growing zones.

In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming, in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.

Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.

However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling. Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has most effect on the weather?

One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and “cold” spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days, it presents hotter or “colder” faces to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward.

Scientists are now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia (慣性) of the earth’s climate. If this is right, the warming effect of carbon dioxide might thus be serving as a useful counter-balance to the sun’s diminishing heat.

36.   It can be concluded that a concentration of carbon dioxide in the atmosphere would ________.

[A] prevent the sun’s rays from leeching the earth’s surface

[B] mean a warming up in the Arctic

[C] account for great changes in the climate in the northern hemisphere

[D] raise the temperature of the earth’s surface

37.   The article was written to explain ________.

[A] the greenhouse effect

[B] the solar effects on the earth

[C] the models of solar-weather interactions

[D] the causes affecting weather

38.   Although the fuel consumption is greater in the northern hemisphere, temperatures there seem to be falling. This is ________.

[A] mainly because the levels of carbon dioxide are rising

[B] possibly because the ice caps in the poles are melting

[C] exclusively due to the effect of the inertia of the earth’s climate

[D] partly due to variations in the output of solar energy

39.   On the basis of their models, scientists are of the opinion that ________.

[A] the climate of the world should be becoming cooler

[B] it will take thousands of years for the inertia of the earth’s climate to take effect

[C] the man-made warming effect helps to increase the solar effects

[D] the new Ice Age will be delayed by the greenhouse effect

40.   If the assumption about the delay of a new Ice Age is correct, ________.

[A] the best way to overcome the cooling effect would be to burn more fuels

[B] ice would soon cover the northern hemisphere

[C] the increased levels of carbon dioxide in the atmosphere could warm up the earth even more quickly

[D] the greenhouse effect could work to the advantage of the earth

Text 3

Some people believe that international sport creates goodwill between the nations and that if countries play games together they will learn to live together. Others say that the opposite is true: that international contests encourage false national pride and lead to misunderstanding and hatred. There is probably some truth in both arguments, but in recent years the Olympic Games have done little to support the view that sports encourages international brotherhood. Not only was there the tragic incident involving the murder of athletes, but the Games were also ruined by lesser incidents caused principally by minor national contests.

One country received its second-place medals with visible indignation af

 << 上一頁  [11] [12] [13] [14] [15] 下一頁