Pentafluorination
五氟化反应
🗣️ 情景例句
Sorry, I have to say good-bye.
我不得不说再见了。
Sober up!
清醒点！
He may never be sure where the next meal is coming from, but his is free from the thousands of anxieties which afflict other people.
他可能从不知道下顿饭有无着落，但他不像有人那样被千万桩愁事所折磨。