1 . 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

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 . 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

4 . 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

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

A．whom	B．which
C．them	D．that

6 . 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

7 . （2015·安徽）Some experts think reading is the fundamental skill upon ________ school education depends.

A．it	B．that
C．whose	D．which

8 . Have you sent thank-you notes to the relatives from _ _ you received gifts?

A．which

B．them

C．that

D．whom

9 . We went through a period ________ communications were very difficult in the rural areas.

A．which

B．whose

C．in which

D．with which

10 . 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）