Qac
abbr. quaternary ammonium compound 季铵化合物（杀菌剂）
🗣️ 情景例句
I think I have fallen in love with someone.
我恋爱了。
When in doubt, play trumps.
举棋苟不定，何妨将一军。
In this part of the cave, they could hear an insistent booming sound which they found was caused by a small waterspout shooting down into a pool from the roof of the cave.
在这儿，他们可以听见一种连续不断的轰鸣声。后来他们发现这是由山洞顶部的一个小孔里喷出的水柱跌落到水潭中发出的声音。