This book ________ be Jim’s.His name is on it.
句意：这本书一定是吉姆的。他的名字在上面。
考查情态动词表推测。must一定，表示肯定的推测；might可能；can’t不可能，表示否定的推测；mustn’t禁止，不允许。根据题中“His name is on it.”，可知书一定是吉姆的。故选A。
This book ________ be Jim’s.His name is on it.
—Look! There are so many people in the restaurant.
—Yes. The food there ________ be delicious.
—____________ we leave the library before 5 o'clock?
—No, you needn't. You can stay here until 5:30.
The biggest challenge weall face is to prevent further environmental disasters. We ________ take action before it is too late.
Listen up, guys!Everyone ________ wear a mask. Go and buy one if you don’t have one.
—Must I return this book before Friday, Sir?
—No, you ________,dear. You can keep it for two weeks.
You’d better take an umbrella when you go out, because it ________rain.
The man _______ be a doctor in this hospital, but I’m not sure.
—Whose notebook is this?
—It ________ be Alan’s. It looks like his.
