单选题若天然气的爆炸下限为 5%体积比,1%体积比等于多少LEL及多少PPM?( )A20%LEL;10000PPMB1%LEL;1PPMC20%LEL;100PPMD5%LEL;10000PPM题目答案A您的答案答案解析暂无解析A