（）属于炸药制品。
A.震源药柱
B.导爆管
C.射孔弹
D.起爆具
参考答案：A, C, D
The maths teacher asked Alice _____ yesterday. [ ]
A. why she misses school
B. why does she miss school
C. why she missed school
D. why did she miss school
说明干燥器的作用.
