You ______ be hungry already—you had lunch only two hours ago!
| A．wouldn’t | B．can’t | C．mustn’t | D．needn’t |
About _____ of the world population is Chinese.
| A．one third | B．one fourth | C．one fifth | D．one sixth |
We should plant more trees on sides of the street.
| A．either | B．both | C．all | D．each |
your help, we can finish the task in time.
| A．Thanks to | B．Thanks for | C．Because | D．Thank |
— It’s one o’clock now. I must go.
— It’s raining outside. Don’t leave it stops.
| A．when | B．since | C．while | D．until |
— Must they clean and tidy the classroom now?
— No, they . It after school in the afternoon.
| A．mustn’t; must clean | B．needn’t; must clean |
| C．mustn’t; need be cleaned | D．don’t have to; can be cleaned |