Ppo
abbr. 聚对苯氧化物（poly - p - phenylene oxide）；胃蛋白酶最大排泄量（peak pepsin output）
🗣️ 情景例句
Hmm. It's probably nothing.
嗯， 也许没什么事。
When the sun comes in, the doctor goes out.
阳光入室，医生出屋。
Will you please have the check certified?
那么请开保付支票好吗？