Students ___________ remain in their seats until all the papers have been collected.

-- Look at the boy running on the ground. Is it David?-- It _______ be him. I saw him go to the teacher’s office just now.

--Listen! Kate is playing the piano in the next room.　　--It _______________be Kate. She has gone to Hangzhou to visit the Cross-sea Bridge.

—Must I finish my homework at school?— No, you_____. you can do it at home

There ________ be any difficulty about passing the road test since you have practised a lot in the driving school.