Nucleus substitution
[化] 环上取代反应
🧩 词语组成解析
substitution
[ˌsʌbsti'tju:ʃən]
n. 代替;代用;替换;<化>取代（作用）;
🗣️ 情景例句
Friends, teachers....
朋友 老师……
Excuse me I couldn't come.
对不起我不能来。
Yes, very hard. Years of hard work, very little food, only a small cold room to live in and never a moment's rest.
是的，境况很不好。多年劳累，食不果腹，斗室寒舍，从无休息。