A.立即 B.聽監(jiān)督指揮 C.根據當時實際情況決定是否 D.留下繼續(xù)工作
A.1.8ppm;預警 B.2.8ppm;預告 C.3.6ppm;警惕 D.4.6ppm;警示
A.5ppm B.10ppm C.20ppm D.100ppm