—Would you like to go hiking with us this Sunday?
—Sure, _______ I am busy.
| A．until | B．when | C．unless | D．since |
— It seems that Mr. Wu is standing there.
— It ______ be him because he called me from Canada just now.
| A．mustn’t | B．can’t |
| C．needn’t | D．shouldn’t |
—Will you please answer the door? It ________ be your sister.
—Sorry, I ________. I’m feeding the rabbit.
| A．must; mustn’t | B．may; can’t |
| C．will; can’t | D．must; needn’t |
--- Listen! David is talking happily with his mother in the next room.
--- It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.
| A．should | B．must |
| C．can’t | D．mustn’t |
— Must I finish my homework now?
— No, you ________. You can go home now.
| A．needn’t | B．mustn’t |
| C．shouldn’t | D．can’t |
-- Must I return the book this week?
-- No, you ______. You can _____ it for 20 days.
| A．mustn’t; keep | B．don’t have to; borrow |
| C．needn’t; keep | D．mustn’t; lend |