﹣﹣﹣I'm proud of our China's Tiangong Station plan.
﹣﹣﹣Me，too.We have taken another step ______ our space dream.（ ）
| A． |
behind |
B． |
towards |
C． |
across |
D． |
besides |
------Must I finish my homework now ?
------No, you _________ . You can do it tomorrow .
| A．can’t | B．needn’t |
| C．mustn’t | D．must |
We be too careful while dealing with these social problems.
| A．may not | B．needn’t |
| C．cannot | D．mustn’t |
——He can write well.
——He_____, but he doesn’t. He’s too lazy.
| A．must | B．mustn’t |
| C．can | D．can’t |
Rick has learned a lot about Chinese culture _____ he came to China.
| A．before | B．when |
| C．until | D．since |
--Sorry, I overslept. I forgot to set the alarm.
--Your clock ________. Perhaps you should buy a new one.
| A．never worked | B．never works |
| C．had never worked | D．is never working |