I had Helen's brother _____ the windows, but Helen had them _____ instead.
| A．to clean； cleaned | B．cleaned； cleaned | C．cleaning； cleaned | D．clean； cleaned |
You can't ______ of being lonely when you don't make an effort to meet people and make friends with them.
| A．explain | B．complain |
| C．confirm | D．admit |
If we work with a strong will, we can ______ any difficulty, however great it is.
| A．overturn | B．overtake |
| C．overcome | D．overwork |
Some smoking and alcoholic drinks are a (n) ______ taste and are not inborn.
| A．gained | B．developed |
| C．acquired | D．grown |
Whatever he explained, he couldn't ______ the policeman that he was innocent.
| A．confirm | B．present |
| C．convince | D．admit |
It ______ ，for there is no one that can be relied on.
| A．let me down | B．let on |
| C．let out | D．let off |