Cindy, you learn physics so well. What’s your ______—Doing a lot of exercises.

There is a belief among students in someuniversities to be a volunteer will help preparethemselves for the future.

Do you know where David is? I couldn’t find him anywhere. — Well. He _____ have gone far-his coat is still here. [ ]

“Mr Smith isn’t coming tonight” “ But he_____”

The plane _______ at 7：00 p.m.，so I have to be at the airport by 6：40 at the latest