单项选择题

Many scientists hold that global warming can be controlled by ______.

A．reducing the polar bear population
B．paying more attention to the earth's rising temperatures
C．reducing carbon dioxide emissions
D．refreezing the polar ice caps

<上一题目录下一题>

热门试题

单项选择题

What has kept temperatures from rising at an even higher rate

A．The absorption of carbon dioxide by natural factors.
B．Human effort to reduce carbon dioxide emissions.
C．Drastically reduced emissions of greenhouse gases.
D．A 10% decrease in the average weight of polar bears.

单项选择题

Which of the following is listed as being evidence for global warming

A．Water shortages in cities.
B．Earlier thawing of lakes and rivers.
C．Increased levels of greenhouse gases.
D．The rapid extinction of the polar bear.