16.(2018临沂)Students ________ enjoy the colorful school life if they study at home instead of going to school.

　　A. mustn't B. can't C. must D.can

　　17.(2018扬州)—I hear you have a home robot.

　　—Yes, it's amazing. It________ do all my housework.

　　A. must B. should C. could D. can

　　18.(2018资阳)—Hi,madam. Can I take the story booksout?

　　—No, my boy. They________ be taken out of the reading­room. It's a rule.

　　A. mustn't B. needn't

　　C. couldn't D. wouldn't

　　19.(2018抚顺)—________ I borrow your dictionary?

　　—Sorry. I've left it at home.

　　A. Should B. Need C. Must D. Could

　　20.(2018东营)—Excuse me,sir, visiting hours are over. You________ leave.

　　—Pardon me, nurse. I didn't hear the bell.

　　A. may B. can C. must D. need

　　21.(2018连云港)—Shall we take a car?

　　—No, we________. It's only five minutes' walk.

　　A. can't B. mustn't C. needn't D. couldn't

　　22.(2018泰州)—Could I smoke here?

　　—Sorry. I am afraid you ________. Look at the sign“No smoking”！

　　A. couldn't B. needn't C. can't D. won't

　　23.(2018齐齐哈尔)—Hi,you________ walk on the grass.

　　—Sorry, I________ do it again.

　　A. can't, will B. needn't,won't C. mustn't,won't

　　命题点二:表推测

　　1.肯定推测：must“一定”。　　　　

　　2.否定推测：can't“一定不”。

　　3.可能推测：may/might(not)“可能(不)”。

　　1. (2018长沙)—Finally,they came back.

　　—They________ be hungry after such a long walk.

　　A. can't B. must 　C. needn't

　　2.(2018武汉)—I still haven't found my pet dog.

　　—I'm sorry to hear that. You________ be very sad.

　　A. can B. should C. must D. will

　　3.(2018福州)—Look at the young lady in red. Is it Mrs.Li?

　　—No. It________ be her. She is wearing a white dress today.

　　A. mustn't B. needn't 　C. can't

　　4.(2018成都)—Is that man Mr.Zhang?

　　—It________ be him. He went to Beijing for a meeting yesterday.

　　A. can't B. mustn't 　C. needn't