Cycloalknes
[建] 環(huán)烷
??? 情景例句
If I have time, I enjoy camping in the wild with my friends.
若時間許可，我愛和朋友到野外露營。
No one can call back yesterday;Yesterday will not be called again.
昨日不復來。
But we still have a problem.
不過我們還是有問題呀。