Asimov had both an extraordinary imagination that gave him the ability to explore future worlds and an amazing mind with which he searched for explanation of everything, in the present and the past.

归纳拓展：定语从句中介词的选择：

1．根据与先行词的搭配。

Soon they arrived at a house, _________________ sat a little boy.

不久，他们来到一座房子，房子前坐着一个小男孩

2. 根据从句中的短语动词搭配。

In the dark street, there wasn't a single person ______ she could turn for help.

　A. to whom B. for who C. to which D. for whom

3．根据句子的意思。

The plane may be several hours late, ______ there's no point in our waiting.

　A. in which case B. in that case C. which case D. which in case

达标检测

1) Gun control is a subject, ______ Americans have argued for a long time.

　A. of which B. with which C. about which D. into which

2) He was educated at the local high school, ______ he went on to Beijing University.

　A. after which B. after that C. in which D. in that

3) 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