I _____ along the pavement yesterday when some stranger came up and asked me the way to the nearest hospital.
| A．am wandering | B．was wandering |
| C．has wandered | D．had wandered |
---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 |
In order to attract more customers, many supermarkets usually sell their goods at a good ______ at weekends.
| A．discount | B．agreement | C．bargain | D．cost |