Anthanthrone
[化] 二苯并[cd,jk]芘-5,10-二酮
🗣️ 情景例句
Life is full of ups and downs.
生活充满起伏。
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。
She works very hard and is very helpful.
她工作非常努力，对同学们帮助很大。