爆炸的三个重要因素是（）。
A、可燃物质
B、空气
C、高温或明火
D、氮气
参考答案：A, B, C
—Excuse me, Mr Black, _____ ?
—He is in his bedroom. [ ]
A. Where is Jim
B. Is Jim in the room
C. How is Jim
D. What's Jim
发生电器火灾怎么办？
