19层煤冲击倾向性鉴定结果为:19层煤具有()倾向性;顶板具有()倾向性。
参考答案:弱冲击;强烈冲击
The passenger was very impolite to the conductor, ____ , of course , made things even worse.
A.who
B.whom
C.which
D.what
进行轴流风机单项连锁试验时,应具备哪些条件?