当硫化氢浓度达到15mg／m3（10ppm)的阈限值时应：（)。

A.10

B.20

C.15

D.100

A.立即安排专人观察风向、风速以便确定受侵害的危险区

B.切断危险区的不防爆电器的电源

C.安排专人佩戴正压式空气呼吸器到危险区检查泄漏点

D.非作业人员撤入安全区

E.协助地方政府撤离居、牧民

A.A.5mg/m3(8ppm)

B.B.10mg/m3(9ppm)

C.C.15mg/m3(10ppm)

D.D.20mg/m3(11ppm)

A.A.15

B.B.30

C.C.150

D.D.300

A.A.10ppm

B.B.15ppm

C.C.20ppm

D.D.25ppm

A.阈限值

B.安全临界浓度

C.危险临界浓度

D.即时危险浓度

A.阈限值为硫化氢检测的一级报警值

B.H₂S的阈限值为10ppm

C.H₂S的阈限值为20ppm

D.H₂S的阈限值为30ppm

A.A.100m

B.B.500m

C.C.1000m

D.D.100m、500m和1000m

A.A.20mg/m2

B.B.30mg/m3

C.C.40mg/m3

D.D.50mg/m4

A.6.7PPm

B.10PPm

C.15PPm

D.20PPm