— Hey! Everyone in the office was at the dinner party in honor of Mr. Charles except you. What happened?
— I ______ after Mike, my colleague. He was badly ill.
| A．have looked | B．was looking | C．would look | D．had looked |
22. —Who______ it be that is knocking at the door?
—It ______ be Father, but I’m not sure.
| A．can; must | B．can; may | C．must; can | D．may; must |
21. He apologized ________ late.
| A．to his teacher to arrive | B．to his teacher for arriving |
| C．at his teacher to arrive | D．at his teacher for arriving |
20. I got up early this morning, but I ________ so because I was not on duty today.
| A．mustn’t have done | B．needn’t have done |
| C．didn’t need to do | D．can’t have done |
19. It’s dangerous to have the fire _______ at home all night long.
| A．to burn | B．burn | C．burned | D．Burning |
18. I decided to write about Chaplin, one of ______ films I had seen several years before.
| A．whose | B．whom | C．that | D．which |