______man can now create radioactive elements, there is nothing he c-考呗网题库移动版

单选题 ______man can now create radioactive elements, there is nothing he can do to reduce their radioactivity．

A．As
B．Whether
C．While
D．Now that

参考答案C

解析: C。人类目前虽然能够创造放射性元素，却不能减少它们的放射性。
考查状语从句。此处应该是一个让步状语从句，所以选择while。whether引导名词性从句，意为“是否”；now that意为“既然”，引导原因状语从句；as可以引导时间状语从句和让步状语从句，但用法与while不同。

单选题 It's a fine day．Let's go fishing,________?

A．won't we
B．will we
C．don't we
D．shall we

单选题 There________a great earthquake in this area, for a lot of buildings were half buried in the earth．

A．must have been
B．will be
C．were
D．has been

单选题 If the ocean were free of ice, storm paths would move further north,________the plains of North America of rainfall．

A．to deprive
B．deprived
C．depriving
D．deprive