Ppf
[医][=pellagra preventive factor]抗糙皮病因子，维生素pp
🗣️ 情景例句
Back soon with a surprise.
接一个惊喜即回。
This windows is junst as small as that one.
这扇窗户刚好和那扇一样小。
Sorry. I wasn't thinking.
抱歉，我没有想到这点。