He ______be lazy, but he can work hard when he feels like it．

—Look at that girl! Is it Susan?—No, it _______ be her. She has gone back to her hometown.

–Someone is knocking at the door. Who ______ it be? --It         be Victor. He has gone to London yesterday.

It’s said that there are plenty of hotels here .There       be any difficulty for you to find somewhere to stay.

All the cars ________ stop when the traffic light is red.