采掘工作面风流中C02浓度达到()时,必须停止工作,撤出人员。
A、1.0%
B、0.5%
C、1.5%
D、0.1%
参考答案:C
句型转换。
1. Chinese people invented the abacus in the sixth century. (改为被动语态)
The abacus in the sixth century by Chinese people.
2. I don't like the movie. The movie is very boring. (合并为含有定语从句的复合句)
I don't like the movie very boring.
3. I used to have long curly hair. (改为一般疑问句)
__________ you __________ to have long curly hair?
4. Few people understood what he said at the meeting. (改为反义疑问句)
Few people understood what he said at the meeting, __________ __________?
5. Mr. King is too busy to go to the concert. (改为同义句)
Mr. King is ___________ busy ___________ he can't go to the concert.