Polyhalogenation
多卤化反应
🗣️ 情景例句
but my work keeps me busy.
但我老是忙于工作。
We were pleased to hear from your letter of 6 August that you were impressed with our selection of toys.
我们很高兴收到你方8月6日来函得知你方对我们的玩具非常感兴趣。
Any messages for me?
有我的留言吗？