You can’t imagine that a well-behaved gentleman __________ be so rude to a lady.

—Do you still go jogging every morning?
—Yes, I can’t think of a _______________ way to start a day.

—Do you think we are going the right way to the Forbidden City?
—Sorry, I’m not sure．But it _______ be．

According to the school rules, no student __________ go out of the school after eleven o’clock at night without the teacher’s permission.

He _______ have taken your car by mistake because he didn’t have the keys.

—I’m just going to finish the work off first.
—Go on if you _______.

---Did Daniel take my football away?
---No, I think it _____ be him, for he doesn’t play football at all.

When Marx was in London, he  __   read at the library for hours.

What a pity! Considering his ability and experience, he ____ have done better.

-Why ________ it rain at weekends?
-Never mind, let’s watch TV at home.