20. The rest of his life was devoted ___ pollution ___more happily .
| A．to prevent , to live | B．to protecting , from living |
| C．to protect , from living | D．to preventing , to live |
1 feel that one of my main duties ______ a teacher is to help the students to become better learners.
| A．for | B．by | C．as | D．with |
___ he did it remains a secret.
| A．What | B．Whom | C．Which | D．How |
It was a pity that the great writer died _________his works unfinished.
| A．for | B．with | C．from | D．of |
That is not ____ I want.
| A．that | B．why | C．what | D．whose |
In order to change attitudes _______ employing women, the government is bringing in new laws.
| A．about | B．of | C．towards | D．on |