A.呼吸顺畅 B.感到无法呼吸 C.面罩充分贴合
A.5%LEL B.10%LEL C.15%LEL D.20%LEL E.25%LEL
A.弃井;弃井 B.弃井;封井 C.封井;弃井 D.封井;封井
A.红 B.黄 C.绿 D.蓝
A.30Mpa;80﹪;30min;0.5Mpa B.20Mpa;70﹪;30min;0.5Mpa C.30Mpa;80﹪;30min;1Mpa D.20Mpa;80﹪;15min;0.5Mpa
A.动物 B.金属 C.土壤