[单项选择]Pollution in water is noticed______.


A. when poisons are poured into water
B. when a great many fish and birds die
C. when the first organisms are affected
D. as soon as the balance of nature is destroyed

[单项选择]Pollution in water is noticed______.
A. when poisons are poured into water
B. when a great many fish and birds die
C. when the first organisms are affected
D. as soon as the balance of nature is destroyed

[单项选择]How do students find out about water pollution


A. They consult pollution experts.
B. They collect water samples.
C. They conduct species surveys.
D. They read books on pollution.

[单项选择]Water pollution, together with old tins and other forms of garbage, （） many problems in our large, industrial city today.
A. is causing
B. have caused
C. have been causing
D. are caused

[单项选择]The way to stop water pollution is______.
A. to put oxygen into the river
B. to realize the serious situation clearly
C. to make the waste materials harmless
D. to make special room in the sea for our waste

[单项选择]Noise pollution is the worst kind of pollution.

[单项选择]What has caused the pollution problem


A. Careless methods of production.
B. Lack of consumer demand for environment friendly products.
C. Millions of tons of glass, paper, plastic and metal containers are produced.
D. Both[A]

[单项选择]Noise pollution generally receives less attention than ______ air pollution.
A. does
B. it does
C. receives
D. it does over

[单项选择]Who is hurt by air pollution


A. The buyer.
B. The seller.
C. Both the buyer and the seller.
D. None.

[单项选择]People can do nothing about pollution.


A. Right.
B. Wrong.
C. Doesn’t say.

[单项选择]

Passage Five
Scientists claim that air pollution causes a decline in the world’ s average air temperature. In order to prove that theory, ecologists have turned to historical data in relation to especially huge volcanic eruptions. They suspect that volcanoes effect weather changes that are similar to air pollution.
One source of information is the effect of the eruption of Tambora, a volcano in Sumbawa, the Dutch East Indies ( the former name of the Republic of Indonesia) ,in April 1815. The largest recorded volcanic eruption, Tambora threw 150 million ton of fine ash into the stratosphere. The ash from a volcano spreads worldwide in a few days and remains in the air for years. Its effect is to turn in coming solar radiation into space and thus cool the earth. For example, records of weather in Eng land show that between April and November 1815, the average temperature had fallen 4.5°F during the next twenty-four months, England suffered one of th
A. of several days' duration worldwide
B. felt mainly in the Dutch East Indies
C. evident in the decreased world temperature
D. immediately evident to the world's scientists