Backflooding
地下水逆流
🗣️ 情景例句
Even when I have a cold, I still have a good appetite.
我就是感冒了，胃口也照样很好！
I know the boy whose father is a painter.
我知道那个男孩的父亲是画家。
What time will the next train leave?
下一班火车什么时候开？