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[单选题]
煤巷、半煤岩巷和有瓦斯涌出的岩巷掘进工作面回风流中,甲烷传感器报警浓度、断电浓度、复电浓度分别是()
A.≥1.0%CH4,≥1.5%CH4,<1.0%CH4
B.≥1.0%CH4,≥1.0%CH4,<1.0%CH4
C.≥1.5%CH4,≥1.5%CH4,<1.0%CH4
D.≥1.5%CH4,≥2.0%CH4,<1.5%CH4
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A.≥1.0%CH4,≥1.5%CH4,<1.0%CH4
B.≥1.0%CH4,≥1.0%CH4,<1.0%CH4
C.≥1.5%CH4,≥1.5%CH4,<1.0%CH4
D.≥1.5%CH4,≥2.0%CH4,<1.5%CH4
第3题
B、≥1.0%CH ,≥1.0%CH ,<1.0%CH
C、≥1.5%CH ,≥1.5%CH ,<1.0%CH
D、≥1.5%CH ,≥2.0%CH ,<1.5%CH
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