——Must I be back home before 6 o’clock?
——No, you ____. Butdon’t be too late.
句意：——我必须在6点钟以前回家吗?——不，你没有必要。但是不要太晚。
本题主要考查情态动词的否定用法。can't不能，不可能，mustn't禁止，needn't不必，won't将不。must构成的一般疑问句，否定回答是没这个必要，用needn’t或don’t have to，故本题选C。
——Must I be back home before 6 o’clock?
——No, you ____. Butdon’t be too late.
—Must I get there on time? I'm too tired to walk on.
—I'm afraid you _______. You can't miss the good chance.
—How do you usually go to school?
—My school is far away.I ________ take the bus to school.
—You ________ takephotos here! Look at the sign. It says “No photos”.
—Sorry, I won’t.
My bike was broken yesterday，so I____walk home．
You________take me to the station. My brother’s taking me.
—According to the schoolrules, the students ________ get their ears pierced.
—I think that’s right.
—In China, many studentsfeel stressed because of too much homework.
—Don’t worry. Our government has realized this problem. I’m sure there________ be good news for them soon.
This book ________ be Jim’s.His name is on it.
—Look! There are so many people in the restaurant.
—Yes. The food there ________ be delicious.
