Unflatness
不平直度
🗣️ 情景例句
I like to study in the library because it's so quiet.
我喜欢在图书馆学习因为那儿很安静。
No safe wading in an unknown water.
未知水深浅，涉水有危险。
A cat? What's its name?
一只猫？它叫什么名字？