题目

下列说法中正确的是( ) A . 液态氧可用作火箭的助燃剂 B . 氧气在空气中的体积分数为78% C . 氧气可以燃烧 D . 鱼类能在水中生存，证明氧气易溶于水 答案：AI was ill that day, otherwise I _______the sports meet.A. took part in B. would have taken part inC. had taken part in D. would take part in