1 . Wind power is an ancient source of energy ________ we may return in the near future.

A．on which

B．from which

C．by which

D．to which

2 . By nine o'clock .all the Olympic torch bearers had reached the top of Mountain Qomolangma, ________ appeared a rare rainbow soon.

A．of which

B．on which

C．from which

D．above which

3 . 在你生命中，如果有一个人你需要对他说对不起，那么就去向他道歉吧。 （apology）

4 . Learning strategies, to ______ （老师们认为） importance, have not yet drawn enough attention of students. （attach）

5 . Gun control is a subject________ Americans have argued for a long time.

A．of which

B．with which

C．into which

D．about which

6 . William Hastie once suggested that history informs us of past mistakes ________ we can learn without repeating them.

A．from which

B．in which

C．with whom

D．for whom

7 . Human facial expressions differ from those of animals in the degree___they can be controlled on purpose.

A．with which	B．to which
C．of which	D．for which

8 . Creating an atmosphere ________ employees feel part of a team is a big challenge.

A．as	B．whose
C．in which	D．at which

9 . Many young people, most _________ were well-educated, headed for remote regions to chase their dreams.

A．of which	B．of them
C．of whom	D．of those

10 . He wrote many children’ s books, nearly half of _______were published in the 1990s.

A．whom	B．which
C．them	D．that