单项选择题
A.干式打眼B.湿式打眼C.湿式凿岩D.干式凿岩
A.进风侧B.上隅C.顶板D.回风侧
A.60%-70%B.65%-70%C.72%-80%D.72%-81%
A.0.1B.0.2C.0.3D.0.4
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