A.氫氣,10m/s B.氮?dú)猓?0m/s C.氫氣,10m/s D.氮?dú)猓?0m/s
A.40%,3 B.40%,4 C.50%,3 D.50%,4
A.0.1 B.0.2 C.0.3 D.0.4