Question

Damage to Ozone layer Gets Worse

In the middle of winter, when snow is falling in many parts of the United States, scientists have sounded a warning to people who plan to spend many hours in the sun this summer. The warning is: The sun’s summertime rays are more dangerous than once thought.

A team of scientists from 80 nations recently reported to the United Nations that a layer of ozone (臭氧层) in the atmosphere, which protects humans from harmful levels of ultraviolet（紫外线） radiation, will be thinner over the United States this summer. The thinner layer allows more ultraviolet rays from the sun to reach Earth. The extra amount of ultraviolet radiation could cause an increase in the number of cases of skin cancer.

Scientists first became concerned about the ozone layer in the mid-1980s when a hole was discovered in the layer above Antarctica during the winter. The hole was caused by chemicals used in refrigerators and air conditioners. When these chemicals are sent out into the atmosphere, they produce gases that destroy the ozone.

Concern about the protective ozone layer rose more recently when data(数据) from satellites and ground stations showed that ozone levels were dropping over areas other than Antarctica. Low ozone levels were recorded in the spring and summer over the United States and over other populated areas in the world.

Although many countries have already begun stopping the use of ozone destroying chemicals, the new findings are expected to advance the timetable for a total ban(禁止) of the chemicals.

1.The scientists have observed the ozone layer ________.

A. since 1980 B. since last winter

C. for about 20 years D. for about one year

2.The ozone layer in the atmosphere can ________.

A. do a lot of good to human beings in many ways.

B. protect humans from diseases caused by bad weather.

C. do a lot of harm to human beings in the summer-time.

D. protect humans from harmful levels of ultraviolet radiation.

3.Scientists first found that there was a hole in the ozone layer ________.

A. above Arctic during the winter in the mid-1980s

B. above Antarctica during the winter in the mid-1980s

C. over somewhere in the north of the equator in 1980

D. over the U.S.A in the summertime in the mid-1980s

4.The damage to the ozone layer was caused by ________.

A. the changeable weather

B. ozone-destroying chemicals

C. chemicals from refrigerators

D. chemicals from air conditioners

Answer

1.C

2.D

3.B

4.B

【解析】

本文属于说明文，科学家们发现大气层臭氧层开始变薄，导致更多的紫外线到达地球，引发更多的皮肤癌，臭氧层变薄的原因是人们大量使用破坏臭氧层的化学物质。

1.细节理解题。根据第三段Scientists first became concerned about the ozone layer in the mid-1980s when a hole was discovered in the layer above Antarctica during the winter.可知，科学家们在20世纪80年代就发现了南极洲上空的臭氧层空洞，因而可知观察臭氧层的历史已经超过30年了，故选C。

2.细节理解题。根据第二段A team of scientists from 80 nations recently reported to the United Nations that a layer of ozone (臭氧层) in the atmosphere, which protects humans from harmful levels of ultraviolet(紫外线) radiation, will be thinner over the United States this summer.可知，臭氧的作用就是减少紫外线到达地球表面，保护人类免受紫外线辐射的有害影响。故选D。

3.细节理解题。根据第三段Scientists first became concerned about the ozone layer in the mid-1980s when a hole was discovered in the layer above Antarctica during the winter.可知，科学家在上世纪80年代的一个冬天在南极洲上空发现臭氧层空洞，故选B。

4.细节理解题。根据第三段The hole was caused by chemicals used in refrigerators and air conditioners.可知，臭氧是被冰箱和空调里面的化学物质所破坏的，故选B。