Ppf
[医][=pellagra preventive factor]抗糙皮病因子，维生素pp
🗣️ 情景例句
And tell them you want to go on the tour that goes down into the canyon.
跟他们说你要参加到峡谷里去的旅游团。
Poor men's words have little weight.
人微言轻。
The deer are farmed for their meat and fur, which are then shipped to many other countries.
饲养鹿的目的是为了获取鹿的肉皮，然后鹿皮会被轮船运往许多别的国家。