—It is a long time ______ I saw you last.
—Yes, and what a pity it is since it will be a long time ______ we see each other again.
| A．before; since | B．when; when |
| C．since; before | D．when; then |
---Let’s go shopping after school.
---______ Call for me at any time.
| A．That depends. | B．Hold on, please. | C．What for? | D．Sounds good. |
---Della, would you like some potato chips?
---No potato chips for me---I’m ______ a diet.
| A．at | B．in | C．on | D．with |
Harry has been reading all day---he ______ be tired.
| A．should | B．has got to | C．has to | D．must |
Children have a natural ______ about the world around them. They are interested in everything.
| A．concern | B．purpose | C．curiosity | D．strength |
---Must I clean the window now?
---No, you ______.
| A．mustn’t | B．needn’t | C．can’t | D．may not |