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 theoffice now.

They ______ him to prepare for the coming exam, but he spent all day playing computer games.

The children were warned of not being too _______ about things you are not supposed to know.

No matter how frequently ________, the works of Beethoven still attract people all over the world.

What do you want to be in the future,Linda ——I want to be ______ pilot like Wang Yaping. Working and giving lessons are so interesting and exciting.