Doctor Ray, as well as other scientists __________ trees for nearly 15 years, but they know only a little about them.
A. study B. studies C. has studied D. have studied
The TV is on, please don’t forget __________ when you leave.
A. to turn off it B. to turn it off
C. turning off it D. turning it off
Benny likes playing tricks ___________ others.
A. on B. at C. for D. to
The film __________ for 5 minutes, we missed the beginning unluckily.
A. is on B. has been on C. begins D. has begun
What do you mean __________your right hand immediately after heard the news?
A. with rising B. with raising
C. by raising D. by rising
There are not many air conditioned buses in the company. The unlined phrase has similar meaning with _________.
A. a few B. few C. a little D. not enough
