题目内容

--May I go to the cinema, Mum?
--Certainly. But you ________ be back by 11 o'clock.

A.
can
B.
may
C.
must
D.
need

C
考查must表示义务的用法。在这一用法中，must意为“必须，应该”，表示必须要做的事，其否定式mustn't表示禁止，即不许对方做某事。

练习册系列答案

相关题目

— May I go to the concert with you?

— I’m afraid not ____ you have a ticket, because I have only one.

A. since　　 B. if　　　 C. unless　　　 D. though

—May I go out to play soccer ball?
—I’m afraid not. You can’t play __ you have finished your homework.

Bill is a lovely boy. He is four years old. There is a park near   1___ house. It is small but beautiful. He  2  with other children in the park every day.
One day, his mother buys new clothes for him.    3   clothes are nice and expensive. Bill is very happy.
“Mum, may I go out     4  play with my friends? I want to show them my    5   clothes.” Asks Bill.
“Yes, please keep your clothes clean.” Says his mother, “I'm going to do some cooking. We will have    6  after your father comes back.”
At about six his father comes back  7   work. Bill goes home for dinner.
“Why do you have so much dirt（泥土）on your  8   ? ” asks his mother when Bill comes into the room..
“Because I have some falls （跌倒）”, answers Bill.
“You mustn't have some falls when you    9   the nice clothes,” says his mother.
“I'm sorry, Mum,”   0   Bill. “But I have no time to take off my clothes when I fall.”