[单项选择]Acid rain


A. immediately kills trees and affects aquatic life in lakes and rivers.
B. deposits various metals iron, mercury, aluminum into the soil.
C. kills forests by weakening them and reduces fish populations.
D. releases sulfur dioxide, nitrogen oxide and into the atmospher

[单项选择]According to the passage, acid rain is


A. a source of pollution.
B. an effect of industrialization.
C. an advantage of industrial society.
D. a deposition of fossil fuels.

[单项选择]Acid rain ______.


A. immediately kills trees and affects aquatic life in lakes and rivers
B. deposits various metals iron, mercury, aluminum into the soil
C. kills forests by weakening them and reduces fish populations
D. releases sulfur dioxide, nitrogen oxide and into the atmosphere

[单项选择]Which of the following is TRUE about acid rain


A. It is acknowledged by scientists to be the most serious pollution problem that human beings now face.
B. Many endangered species are on the verge of extinction because of acid rain.
C. Acid rain is composed of sulfur dioxide and nitrogen oxides mixed with water vapor found in the upper atmosphere.
D. Acid rain is mostly found in the United States and Canada.

[单项选择]The damaging effects of acid rain are felt less in the West because _________.


A. Western parts produce much less than a quarter of sulfur oxide emissions
B. Western soils can neutralize the acid
C. Westernly wind spread participants out of the western regions
D. chemical industry is less developed in the western states

[单项选择]The least serious damage caused by acid rain is _________.


A. poisoning of plant roots
B. leaching of heavy metals
C. changing the blood chemistry in
D. corrosion of metal structures

[单项选择]Why is acid rain little understood______
A. Because it is a new phenomenon
B. Because it is not frequent enough
C. Because its formation is complex
D. Because it is difficult to study it

[单项选择]

Text 1
Acid rain, which is a form of’ air pollution, currently becomes a subject of great debate because of widespread environmental damage for which it has been blamed. It forms when oxides of sulfur and nitrogen combine with atmospheric moisture to yield sulfuric and nitric acids, which may then be carried long distances from their source before they drop in the form of rain. The pollution may also take the form of snow or fog or fall down in dry forms. In fact, although the term "acid rain" has been in use .for more than a century--it is derived from atmospheric studies that were made in the region of Manchester, England--the more accurate scientific term would be’ acid deposition.’The dry form of such deposition is just as damaging to the environment as the liquid form.
The problem of acid rain originated with the Industrial Revolution, and it has been growing ever since. The severity of its effects has long been recognized i
A. acid rain has caused air pollution
B. acid rain has caused widespread environmental damage
C. acid, rain has become a much studied subject
D. acid rain travels in all directions before it rains down

[单项选择]In this densely populated city, acid rain is ______; it is a sign both of industrialization and pollution.
A. prevalent
B. productive
C. popular
D. possible

[单项选择]According to the passages acid rain _________.


A. adds minerals to the grain
B. travels with the prevailing westernly wind
C. leads to birth defects in fish
D. and its formation have been fully understood

[单项选择]

What makes it rain Rain falls from clouds for the same reason anything falls to Earth. The Earth’s gravity pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.
Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about chaotically without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The average size of a cloud droplet is only 0. 0004 inch in diameter. It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of mo
A. unpredictable
B. perplexing
C. independent
D. abnormal