We should ________ ‘Thank you’ when we borrow something from someone.

Jeremy Lin __________ an unknown basketball player in New York Knicks for quite a long time.

Tom wants to know_____________. — I don’t know, either. He said he would phone me as soon as he came back.

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

There is no doubt ________ Tom is a good clever boy.