Qac
abbr. quaternary ammonium compound 季銨化合物（殺菌劑）
??? 情景例句
I got the first round.
第一輪我請的客。
Do you think it fits OK?
你看合身嗎？
Tell Mary we'll be late for dinner this evening.
你告訴瑪麗，今晚吃飯將晚到一會兒。