You are sure to make great progress________you stick to your plans for your study[ ]

Look at this picture. There is a bridge_______ the river, and there are three birds_______ the tree.

Listen! Tom is singing in the next room.–It _______ be Tom. He has gone to Shanghai.

The novels written by Mo Yan sell best now, but yearsago no one could have imagined he _____ the Nobel Prize for Literature.

May I go to the movies tonight, mum? — You can when you ____ your homework