A.30mg/m3(20ppm) B.75mg/m3(50ppm) C.150mg/m3(100ppm) D.15mg/m3(10ppm)
A.3.4mg/m3 B.4.4mg/m3 C.5.4mg/m3 D.6.4mg/m3
A.3 B.5 C.1 D.10
A.口罩 B.正压式空气呼吸器 C.滤罐式呼吸装置 D.防毒面具
A.兴奋 B.抑制 C.坏死