爆炸材料箱必须放在什么地点？
参考答案：
顶板完好、支架完整、避开机械设备、避开电气设备。
描述你的朋友。
______________ is my friend.
She's ______________.
She has ______________.
She likes ______________.
There must be ______ book which could help .
A．some
B．any
C．one
D．one useful
