Perfluoroalkanes
全氟烃类
🗣️ 情景例句
Go for the first prize! i know you are good enough.
争取拿头奖，我知道你行。
It was after dark when we got back,and we were all tired.
我们回来时天已经黑了，并且我们都很疲倦。
What jobs do women do in Britain?
在英国，妇女们都干些什么工作？