If hydrogen is present ,as is often the case for gases with a synthetic admixture,the hydrogen content aslo needs to be known.

 
  • 如果存在氫氣,也需知道其含量,在含人工摻合物的氣體中常有這種情況。
今日熱詞
目錄 附錄 查詞歷史
国内精品美女A∨在线播放xuan