It is usually warm in my hometown in March, but it _____ be rather cold sometimes.

---Look at the glasses on the desk. Are they David’s?---They      belong to him. I saw him go out with glasses just now.

 —Why are you late again?—Something happened to our friend Wang Fei. I _____ to help him.

--Why are your eyes so red? You _______ have slept well last night.---Yeah, I stayed up late writing a report.

— Is Mr. Smith driving here?  —I’m not sure. He ______ come by subway.