You have seen Helen in her office this morning because she’s been out of town for two weeks.
| A．needn’t | B．mustn’t |
| C．mightn’t | D．couldn’t |
--____ did he send this letter to you? ---By mail
| A．Which | B．Why | C．What | D．How |
--Let’s go to see our teacher. ---_____.
| A．That will do | B．That’s all | C．That’s right | D．All right |
--Have you handed in your composition? ---____.
| A．Yes, I handed | B．No, I didn't | C．Yet not | D．Not yet |
I have been looking for this book for months, and _____ I have found it.
| A．at least | B．in no time | C．at last | D．at present |
Air and the sun's rays create much distortion, and whatever tends to _____ their influence is useful to the astronomer.
| A．exclude | B．eliminate | C．extinguish | D．impose |