Chrysofluorene
[化] 柯芴; 11-H-苯并[α]芴
🗣️ 情景例句
What time?
什么时候
He has been to America.
他曾去过美国。[表示曾经有过的经验]
I was very tired when I arrived home. I'd been working hard all day.
我到家时非常累。我一整天都在玩命地干！