She learns something _____ art and history on Sundays.[ ]

Tell Jack I will wait for him at the school gate.—______ he doesn’t come?

With the help of the smart phones, you ____ video chat with your friends on the phone.

Whose is that book? —-It _________ belong to Lucy. Her name is on it.

Has Sam finished his report?—I have no idea. He _______ it in his office the whole morning.