My sister met him at the street yesterday afternoon, so he __________ your lecture.

I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.

--Guess what! Tan Weiwei failed in the last round of the Super Girl Contest.---How _______ it be? She is second to none in singing in my opinion.

－What do you think we can do for our aged parents?－You_______ do anything except to be with them and be yourself.

–Who is the tallest boy?–It ______  be John. Because John is of medium height..