Quaterisation
季铵化反应
🗣️ 情景例句
Nice to meet you, Mrs. Cooper.
很高兴见到你， Cooper太太。
There's no such thing as a free lunch.
天下没有白吃的午餐。
Oh, good evening, Lucy. Come in. Nice to see you!
噢，晚上好，露茜。请进。见到你真高兴！