（）是能够用于带电灭火的灭火器材。
A.泡沫灭火器
B.二氧化碳灭火器
C.干砂
D.干粉灭火器
参考答案：B, C, D
－Teenagers should be allowed to go out with their friends in the evening.
－______. It's not safe enough. [ ]
A. I agree
B. I think so
C. I don't know
D. I disagree
如果烟舌工作面与两侧面出现磨损，烟支直径会控制不好，容易产生烟支（）。
