Pentabromination
五溴化反应
🗣️ 情景例句
I don't know.
我不知道。
The tongue of idle persons is never idle.
懒汉的舌头并不闲。
Mathilde! I didn't know. I'm sorry. But what happened?
玛蒂尔德！我还不知道这些情况哩。我真难过。但是，这是怎么回事呢？