下列哪种灭火器不适用于扑灭电器火灾（）
A.二氧化碳灭火器
B.干粉剂灭火剂
C.泡沫灭火器
参考答案：C
— It's been raining for a whole week. I think it'll get fine soon.
— _____. We are getting into the rainy season now.[ ]
A. Yes, it will
B. Of course not
C. It's possible
D. It's hard to say
中层重要天气预告图（SWM）供飞行高度（），（）的中空飞行使用.
A.小于等于FL250，大于FL150
B.小于等于FL250，大于FL100
C.小于FL250，大于等于FL100
