Many countries are increasing their use of natural gas , wind and other forms of ______.
A. power B. force C. energy D. strength
The fact that many college graduates get lower pay than some workers has ______ a heated discussion.
A. set out B. set about C. set up D. set off
I have no idea ______ it is that makes him puzzled.
A. how B. what C. why D. which
He sat at the desk, __________ a novel.
A. read B. to read C. reading D. reads
______ tourism developing, more and more people prefer to go travelling for a holiday.
A. As. B. With C. Upon D. For
.--- I was lucky the win a gold medal in the800-metre race.
--- You ____ through hard training.
A. must go B. should go C. must have gone D. should have gone.
