He ________ if he works hard for the people.

-Listen! Is Mary playing the piano in the room?  --No. It ________ be Mary. She has gone to Hong Kong.

The police still haven’t found the lost child, but they’re doing all they             .

Liza _ ___ well not want to go on the trip---she hates traveling.

 ---Must I be back home before 6 o’clock? ---No, you ____. But don’t be too late.