—When did you start your math homework?—One hour ago,but I________it yet.
It’s hard work building a bridge over the river.
Tom and Jerry is one of those cartoons _____ you laugh.
— Do you know when Mr Wang back? — Sorry, I don’t know. But I’ll tell you as soon as he back.
You should try to speak English as as possible.
Look! There are a lot of children on the playground.