Who’s that?—My sister. ______ works in a factory.

It’s hard to finish the work in a day. You’d better ____ your friends to help you.

You don’t look very __________ .Anything wrong ?—Nothing . I’m just a little tired.

Children shouldn’t watchTV.

Is the man standing outside the teacher’s office Mr. Zhou? –No, it ______ be him. He has gone to Hong Kong for an academic conference.