O2
[医] 氧(8号元素); 两眼
🗣️ 情景例句
How long will it take for my mail to reach its destination?
我的信件到达目的地要多久？
What is not wisdom is danger.
不智的事是危险的。
Ethanol is more effective at a concentration of 50-70 percent;
乙醇的浓度为50％至70％时比较有效，