如何处理喷射混凝土支护时围岩渗水问题?
参考答案:
根据水量大小可采取压气清扫;快凝水泥砂浆封堵;导水。
不属于人事测评方法通常采用的指标是()。
A.效度
B.普遍性
C.实用性
D.公平程度
They have never been to Beijing, _____? [ ]
A. have they
B. haven't they
C. do they
D. don't they