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
Hi, Susan.
嗨， Susan。
I'm single.
我现在单身。
They had a definite meaning, for they were as near as early man could get to writing.
它们有着一定的含义，因为它们已接近古代人的文字形式。