Fluoridizer
氟化剂, 氟化器
🗣️ 情景例句
when it's very cold out.
冬天外面很冷的时候。
I meet the boy whose aunt is an accountant.
我遇到那个男孩的姑妈是会计。
Being a mother is not easy.
做一个母亲是不容易的。