Ppa
abbr. 苯丙醇胺（phenyl-propanolamine）；并行处理自动机（Parallel Processing Automata）；实验性反应堆（Preliminary Pile Assembly）
🗣️ 情景例句
The water's pretty deep here.
这里水相当深。
Enough is as good as a feast.
知足常乐。
Oh? What happened?
哦？发生什么事了？