—“What courses are you going to take next semester if you want to receive enough credits to get your degree?”—“I don’t know. But it’s about time      on something.”

——This wall of air is an effective answer to the problem and it ____ work.——But it is a question to put such a wall of air around the statue.

They        have arrived at lunchtime, but their flight was delayed.

The professor ________at 8 o’clock，but he has not shown up yet，which worries all of us.

(2013·高考浙江卷)I ________ myself more－it was a perfect day.