Dentists suggest brushing teeth at least twice a day to _____ them from decaying.

A new technique （ ）, the output as a whole increased by 20 percent.

There is a warning at the bottom of the form that applicants are requested to hand in their forms _____ person.

If we cannot agree upon our Christmas activities right now, why don’t we （ ） it in next week’s class meeting?

Mr. Phillips caught up with the boy in the corridor and （ ） his hand on his shoulder.

The two parties haven’t reached any agreement, but decided to set another date for （ ） talks.

（ ） is careless when disposing of his wastes.

Solar energy is a new kind of energy _____ that we can use to replace the traditional energy.

（ ） does it take you to wash all the dishes?

It is a fact _____ most deaths from lung cancer are caused by smoking.

Humble （ ） it may be, there is no place like home.

He studies so hard to avoid （ ） at the bottom of the class.