单项选择题

A．Because the CFCs directly damage the people’s health.……

Why should governments ensure the careful handling and recycling of the CFCs now in use

A．Because the CFCs directly damage the people’s health.
B．Because the CFCs are poisonous chemicals.
C．Because the production of the CFCs costs a lot.
D．Because the CFCs can attack ozone by liberating atoms of chlorine.

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热门试题

单项选择题The best way to save ozone is ______.

A．that CFC manufacture is completely forbidden
B．that the production of CFC is reduced
C．to find substitutes for CFCs
D．to reduce the danger of CFCs

单项选择题At first, locomotives could not popularize themselves because they ______.

A．could not bring profits or save much labor
B．attract people
C．only caught some people’s interest
D．were not welcome

单项选择题In a true sense, plateways are the earliest and most primitive railways invented by ______.

A．industrial workers
B．George Stephenson
C．the miners
D．the miner’s work

单项选择题The multi-tube boiler system made the Rocket, Robert’s locomotive, ______.

A．powerful
B．achieve a speed of 30 miles an hour
C．acquire 25 little tubes
D．good for hauling trains

单项选择题According to the passage, how do students in class often react to another student's research

A．They react the way they do to any other research.
B．They are especially critical of the quality of the research.
C．They offer unusually good suggestions for improving the work.
D．They show a lot of sympathy for the student researcher.