There is somebody knocking at the door. Who________ it be?—I’m not sure. It ________ be a postman.

The number of the workers here ___ 200. Half of them ____under 30 years old.

How long do you think it will be _______ we get the loan?—Perhaps two or three months.

The girl doesn’t do any housework ______ Monday ______ Friday.[ ]

Don’t _____ your hands from the window when you are on a bus.