Have you watered the plants yet, Kathy? —Yes. I ________ that this morning.

I’m going to buy a car. Any advice, Charlie?—Well, it depends on(根据) ________. If money isn’t a problem, you can buy a BMW.

Many people agree that_______ knowledge of English is a must in ______international trade today.

The windows are broken and need to be repaired.— I think so. They can hardly _____ the cold now.

Listen! Someone is knocking at the door. Who _____it be?—It _____be Tom. He phoned to visit me this evening.