that young babies learn to do things because certain acts lead to awards.

What’s the matter ________Sonia?[ ]

Look! The light is still on. Is Mr Wu working in his office？—No, it _____ be Mr Wu. He has gone to Nanjing for a meeting.

I didn’t see you at the party yesterday. Why? — Because I ________ for an important person from America at that time.

Which basketball player do you like best, Kobe, James or Jordan? — _______ of them .Lin shuhao is my favorite.