This book _______ be Tom’s. Look! His name is on the cover.

(2013·安徽安庆三模)—She looks very happy.She________have passed the exam.—I guess so.It’s not difficult after all.

He bought some books in the bookstore and his father________ him a lot of money.

 — Listen! Is that Linda singing in the next room?— No, it ________ be her. She is still in Shanghai.

As a well-known Chinese saying goes, “If you want to be rich, you______ first build roads.”