Helen ______ books at the moment.
— Look at the boy playing basketball on the ground. Is it George? — It ________ be him. He told me he would play basketball after class, but he’s not sure.
–Look! A man is cutting a tree on the moon. --It ______ be true. The teacher said there is no air on the moon.
----Must I finish the work today, Mom? ----No, you _______________. You can finish it tomorrow.
—May I take photos in the museum? —No, you . You obey the rules here.
—who is the man over there ? Is it Mr.Wang ? —No, it _____be him .Mr.Wang is much fatter.