Ppf
[医][=pellagra preventive factor]抗糙皮病因子，维生素pp
🗣️ 情景例句
It's unsafe for girls to go out alone at night.
女孩子晚上一个人外出很危险的。
He will be indignant about the injustice.
他可能会因不公平的判决而生气。
but the took a long time to send them Meanwhile,
但过了好长时间不见他把数字寄来，