[单项选择]The dark smoke that comes out of stacks or from a burning dump contains tiny bits of solid or liquid matter. The smoke also contains many gases, most of which cannot be seen. Altogether, they make up the serious problems of air pollution. In so many places it keeps us from seeing the sun, irritates our eyes, causes us to cough, and makes us ill.
Air pollution can spread from city to city. It even spreads from one country to another. Some northern European countries have had "black snow" from pollutants that have traveled through the air from other countries and have fallen with the snow. So air pollution is really a global problem.
Air pollution can kill babies, older people , and those who have respiratory (呼吸道的) diseases. In London, in 1952, four thousand people died in one week as a result of a serious air-pollution episode. In 1948, in the small town of Donora, Pennsylvania, twenty people died in a four-day period of bad air pollution.
At levels often found in cities
A. Illinois
B. Pennsylvania
C. New Jersey
D. Washington

[单项选择]The dark smoke that comes out of stacks or from a burning dump contains tiny bits of solid or liquid matter. The smoke also contains many gases, most of which cannot be seen. Altogether, they make up the serious problems of air pollution. In so many places it keeps us from seeing the sun, irritates our eyes, causes us to cough, and makes us ill.
Air pollution can spread from city to city. It even spreads from one country to another. Some northern European countries have had "black snow" from pollutants that have traveled through the air from other countries and have fallen with the snow. So air pollution is really a global problem.
Air pollution can kill babies, older people , and those who have respiratory (呼吸道的) diseases. In London, in 1952, four thousand people died in one week as a result of a serious air-pollution episode. In 1948, in the small town of Donora, Pennsylvania, twenty people died in a four-day period of bad air pollution.
At levels often found in cities
A. pilots become ill
B. visibility is reduced
C. engines fail.
D. the air is too hot

[填空题]Petroleum that comes directly from deep in the ground is called ______.

[单项选择]A. It comes regularly from its donors. B. It has been drastically cut by NASA.
C. It has been increased over the years. D. It is still far from being sufficient.

[填空题]Where may this letter come from It comes from ______ about computer.

[判断题]Wool comes from sheep and cows.

[填空题]Students’ pressure sometimes comes from their parents. Most parents are well (36) but some of them aren’t very helpful with the problems their sons and daughters have in (37) to college, and a few of them seem to go out of their way to add to their children’s difficulties.
For one thing, parents are often not (38) of the kinds of problems their children face. They don’t realize that the (39) is keener, that the required (40) of work are higher, and that their children may not be prepared for the change. (41) to seeing A’s and B’s on high school report cards, they may be upset when their children’s first (42) college grades are below that level. At their kindest, they may gently (43) why John or Mary isn’t doing better, whether he or she is trying as hard as he or she should, and so on. (44) .
Sometimes parents regard their children as extensions of themselves and (45) <