—Look! The man at the gate ______ be our headmaster. He is always standing there every morning.—No, it ______be him. He is holding a meeting in the office now.

— Who’s that man over there standing in the garden? Is it Mr. White?—It __________ be him. He has gone to Shanghai on business. 

--Whose backpack is this? ---It            be Jim’s. Look, his student’s card is in it.

Tom’s score on the test is the highest in the class. He _____.

— Listen! Helen is singing in the classroom.—It _______ be Helen. She has gone to Shanghai.