—A shy boy like John ________ give up a secure job and start his own business!—Yes，nobody had expected that. 

Two weeks ago, I bought a bicycle. If you live in town, it is often faster than a car and you           worry about parking. 

--Whose T-shirt is this? --It       be John’s. It’s much too small for him.

One of the National Health Regulations is that public schools ______ actively create conditions for sports facilities opened to the public.

--Listen! Someone is knocking at the door. Who _____it be?---It_____be Tom. He phoned to visit me this evening.