A.10~20ppmB.100~200ppmC.150~300ppmD.200~350ppm
A.0.45~0.55MPaB.0.5~0.6MPaC.0.55~0.65MPaD.0.6~0.7MPa
A.必須辦理“高處作業(yè)許可證B.必須經(jīng)體檢合格C.必須穿戴好安全帶,戴好安全帽,隨身攜帶得工具.零件.材料等必須裝入工具袋D.必須佩戴防毒用具