采煤工作面甲烷传感器复电浓度为（）

A.10

B.20

C.30

D.50

A.0.5

B.1.0

C.1.5

A.1%

B.0.5%

C.1.5%

A.≥0.5

B.≥0.8

C.≥1.0

D.≥1.5

A.≥1.0%

B.≥1.2%

C.≥1.5%

D.≥1.8%

A.≥0.5

B.≥0.8

C.≥1.0

D.≥1.5

A.0.75%

B.1.0%

C.1.5%

A.≥0.5

B.≥0.8

C.≥1.0

D.≥1.5