Wallerite
墨铜矿
🗣️ 情景例句
It's true.
对。
How would you like me to cut your hair?
我给你理发，好吗？
Imagine a pen attached to the weight in such a way that its point rests upon a piece of paper on the floor.
假定把一支笔拴在重物上，笔尖落在地板上的一张纸上，