.（湖南卷23）. You_________ buy a gift , but you can if you want to.
| A．must | B．mustn’t | C．have to | D．don’t have to |
A container weighs more after air is put in,_____proves that air has weight.
| A．as | B．it | C．that | D．which |
I’ll take you to a shopping center nearby_____you may buy all_____you need.
| A．that; that |
| B．which; that |
| C．where; which |
| D．in which; 不填 |
Do you know the reason_____she didn’t attend her boyfriend’s birthday party yesterday?
| A．why | B．which | C．for that | D．for why |
What especially impressed us was the way_____the girl studied foreign languages.
| A．不填 | B．which | C．by which | D．how |
The young boy got himself into a dangerous situation_____he might lose control over his sports car.
| A．that | B．which | C．when | D．where |