干粉灭火器使用时的操作关键是()。
A、拉出插销
B、开启提环
C、轻轻抖动几下
D、将灭火器颠倒过来
参考答案:B
_____ It /it was cool, so he _____ to the movies. [ ]
A. /, went
B. Because, went
C. Because, go
D. Because, goes
吊运成批零散物件时,必须绑扎牢圃,防止吊运中散落。