一      I turn on the TV for you，Grandpa?一Yes，thanks a lot，my dear. You’re so considerate.

It was playing video games that took the boy too much time that he          have spent learning．

——Do you know where David is? I couldn’t find him anywhere. ——Well, he_______ gone far—his coat’s still here.

My sister met him at the cinema yesterday afternoon, so he       your lecture.

---Look. The man at the gate _____ be our headmaster. He is always standing there every morning.---No. it ____ be him. He is having a meeting in the office now.