Minister Bill De Blasio in office fewer than 48 hours when he came face to face with his biggest challenge in his life．
| A．has been | B．had been | C．would be | D．is |
As a graducate in computer science, he ___ to work out the problem.
| A．wouldn't have failed | B．can't have failed | C．mustn’t have failed | D．might not have failed |
I don't think ___ possible to master a foreign language without much memory work.
| A．this | B．that | C．its | D．it |
If you want to borrow a football after school, your student card ___ here.
| A．has to leave | B．must leave | C．has to be left | D．must be left |
You ___ me, but since you have,I’ll keep it secret from others.
| A．needn’t have told | B．didn't need to tell | C．wouldn't have told | D．couldn't have told |
If you have something important to do, you ___ waste any time.
| A．needn’t | B．mustn’t | C．may not | D．won’t |