The Department is also deeply _____ in various improvement schemes.
The factory used 65 percent of the raw materials, the rest of which __________ saved for other purposes.
The secretary and principal __________ at the meeting now.
We all think Mr. Smith __________ a new house if more new houses __________.
If better use is __________ of your spare time, you'll make great progress in your study.
English is difficult __________ well in a short time.