---- ________ we go swimming in Xishuanghu Lake today?  ---- Oh, no. It’s ________ cold to swim on such days. I will catch a cold. 

If you love someone, why ______ you chain him to your side, control his emotion, and even make him center on you?

--Is the man standing outside the teacher’s office Mr. Zhou?  --No, it ______ be him. He has gone to Hong Kong for an academic conference. 

 — Is Jim coming by train?  — I’m not sure. He_____ drive his car.

---Must Jack come to sign his name on the paper?---Yes, he_____ .