Complete the following sentences.

　　1)He never comes except when he is　　　 (有麻烦).

　　2)The teacher 　　　 (费尽心血)explain the difficult question to us.

　　3)The boy is 　　　(有困难)getting along with his stepmother.

　　3. Why did Nelson Mandela turn to violence to make black and white people equal? 曼德拉为什么付诸于武力去实现使黑人白人平等的理想?

　　【观察思考】

　　1)Nobody will turn against his country. 没有人会背叛自己的国家。

　　2)Please turn down the television. 请把电视机的音量调小点儿。

　　3)He turned down my suggestion without hesitation. 他毫不犹豫地拒绝了我的建议。

　　4)The child picked up a purse and turned it in to the policeman. 那个孩子捡到了一个钱包, 然后把它交给了警察。

　　5)The farmers are turning waste land into rich fields. 农民们正把荒地变成肥沃的田地。

　　6)Don't forget to turn all the lights off before you go to bed. 在你上床之前, 不要忘记把所有的灯都关上。

　　7)The man turned over and went to sleep again when the telephone rang. 当电话铃响的时候, 那个人翻了个身, 又睡着了。

turn to 　　

turn against 　　

turn down 　　

turn in 　　

turn . . . into . . . 　　

turn off 　　

turn on 　　

turn over 　　

in turn 　　

　　【尝试运用】

　　1)In the new city there wasn't a single person　　　 the poor boy could turn for help.

　　A. that　　　　　　

　　B. who

　　C. from whom

　　D. to whom

　　2)用适当介词填空。

　　(1)Nothing could make the brave man turn 　　　 his motherland.

　　(2)Don't rush. Please wait in line and get on the bus 　　　 turn.

　　(3)He asked his teacher to give him the chance once more but his teacher turned him 　　　.

　　(4)Be sure to turn the lights 　　　 when you leave the classroom.

4. The scientist from whom I learned a lot never lose heart when he was in trouble.