Question

閱讀理解

　　In the middle of winter, when snow is falling in many parts of the United States. Scientists have sounded the sun this summer. The warning: The sun’s summer time 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(臭氧層) in the atmosphere, which protects humans from harmful levels of ultraviolet (紫外的) 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 Antarctic 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 (數(shù)據(jù)) from satellites and ground stations showed that ozone levels were dropping over areas other than Antarctic. 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 more than 10 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．a(chǎn)bove Arctic during the winter in the mid-1980

B．a(chǎn)bove Antarctic during the winter in the mid-1980

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

D．over somewhere in the summer time 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

5．Which of the following is NOT true?

[　　]

A．The use of ozone-destroying chemicals have already been stopped.

B．The ozone levels in the spring and summer over the USA were low.

C．More and more people have begun to protect the natural surroundings.

D．Many countries have already taken measures to protect ozone layer.

Answer 1

答案：C;D;B;B;A
解析：

1．文章第三段中告訴我們：科學家們開始關注臭氧層是在20世紀80年代中期，所以A項（自從1980年起）、B項（從去年冬天起）、D項（大約一年）都不正確，只有C項符合題意，故選之。 　　2．根據(jù)文章第二段第一句：…which protects humans from harmful levels of ultraviolet radiat ion, …（臭氧層）保護人類免受有害的紫外線的輻射……這一定語從句可以明顯地看出臭氧層的作用為D項。 　　3．本題為事實辨認題。第三段的第一句很清楚地告訴我們：科學家們在20世紀80年代中期，發(fā)現(xiàn)了南極上空的臭氧層里的空洞。故選B項為正確答案。 　　4．本題可采用排除法解。A項文中并未提及，顯然可以排除；C、D兩項只是原因的一個方面，較為片面，也可排除；惟有B項是對C、D兩項的綜合，故選之。而且，根據(jù)第三段最后一句也可得出B項為正確答案。 　　5．文章最后一段告訴我們：盡管許多國家已經(jīng)開始停止使用破壞臭氧層的化學物質(zhì)，但仍希望發(fā)現(xiàn)新的替代品把全面禁止這種化學物質(zhì)推向一個新臺階。可見，破壞臭氧層的化學物質(zhì)并沒有完全被停止，A項與文中事實不符，故選之。