Foryearsscientistshavebeenworr-优题课

For years scientists have been worried about the ______ of air pollution on the earth's natural conditions.

A．effect	B．result
C．account	D．cause

科目英语题型单选题难度中等

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Nearly a month had gone by____they showed some sign of giving up the price for which they had held out.

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In the years____, the city government will take effective measures to bring the price of the house under control.

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According to some doctors, one of the ways to prevent us from growing old is to make sure
that our brains get enough___.

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We are ____faced with the necessity to recognize that having more people implies a lower standard of living.

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Although many people view conflict as bad, conflict is sometimes useful _______ it forces people to test the relative merits of their attitudes and behaviors.