手动切割机专用于切割（）的施工机具。
A．饰面砖
B．水泥板
C．大理石
D．花岗石
参考答案：A
--Have you got the leaving time of the train for me?
---Yes, but you’d better ____of it by yourself.
A．make sure
B．be sure
C．to make sure
D．be certain
三段式电流保护三段的区别是什么？
