1 . 他们一定是在森林里迷路的孩子；否则，他们就会按计划去湖边露营了。
They ________________ the children lost in the woods; otherwise, they would have been at the lakeside camp as scheduled.

2 . I have lost my wallet. I ________ it somewhere just now.

A．must drop	B．must have been dropped
C．must have dropped	D．should have dropped

4 . 她断定他准是把包落在火车上了。
She reasoned that she ________________ on the train.

5 . Mary’s bedroom is so tidy. She________have cleaned it yesterday.

A．must

B．should

C．need

D．would

6 . —Why didn’t you come to Mike’s birthday party yesterday ?
—Well, I________, but I forgot it.

A．should

B．must

C．should have

D．must have

7 . 选词填空
1. —Must I finish the task right now?
—No，you ________ (don’t have to/mustn’t)
2. It’s so near. We ________ have taken a taxi.(shouldn’t/can’t)
3. You ________ have spent so much time playing computer games.(mustn’t/oughtn’t to)
4. ―Shall I leave the room so that you two can talk?
―No, you ________.(mustn’t/needn’t)
5. He ________ have missed the train; he arrived atthe train station two hours earlier.(can’t/mustn’t)
6. You ________ start at once if you want to catch the bus.(have to/ought to)
7. They ________ stay in the office last night because of the snowstorm.(had to/must)
8. We _______ have helped him; in that case, he would have been able to finish the work.(should/can)
9. He finished all the work himself; in fact, he ________ have asked his friends for help.(need/could)
10. Something terrible ________ have happened if Li Chang was not coming to eat in his restaurant as he always did.(have to/must)

8 . Something ________ have happened to Mary—She’s been crying all morning. (Possibility) (用适当的词填空)

9 . ________________ (肯定有人打开了笼子). The dog couldn’t have escaped on its own. (根据汉语提示完成句子)

10 . —— Guess what? I’ve won the third prize in the writing competition in Tianjin area.
—— You don’t say. I know you are not good at English. You ______ great efforts!

A．should have made

B．must have made

C．might make

D．could make