--Whose backpack is this? ---It            be Jim’s. Look, his student’s card is in it.

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

As students, we ________ study hard to make our country more beautiful and stronger.

—Tom often drives carelessly.—Tell him he ________ answer for it if he goes on behaving like that. 

He ______ it on schedule, but somehow he fell behind.