—Do you think we are going the right way to the Forbidden City?—Sorry, I’m not sure．But it _______ be．

This pair of shoes ______ Li Gang’s ．It’s too big for him ．

Living in a fast-paced world, we                  get left behind if we stop learning.

 －Is Mr. Li in his office ?－No, he __________ in the office. He’s ill in hospital.

--Listen! Kate is playing the piano in the next room.　　--It _______________be Kate. She has gone to Hangzhou to visit the Cross-sea Bridge.