单选题：Great as Newton was，many of his ideas ________ today and are

题目内容：
Great as Newton was，many of his ideas ________ today and are being modified by the work of scientists of our time． A．are to challenge
B．may be challenged
C．have been challenged
D．are challenging

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答案解析：

Nonsmoking mothers were selected because the effect of smoki

Nonsmoking mothers were selected because the effect of smoking on PAHs was uncle

分类：成人英语三级  题型：单选题
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This kind of animals are on the verge of extinction, because

This kind of animals are on the verge of extinction, because so many are being k

分类：成人英语三级  题型：单选题
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Techniques to harness the energy of the sun are being develo

Techniques to harness the energy of the sun are being developed.A．convert B．stor

分类：成人英语三级  题型：单选题
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The doctors have abandoned the hope to rescue the old man.

The doctors have abandoned the hope to rescue the old man.A．gave away B．given up

分类：成人英语三级  题型：单选题
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