"Shuisheng, come with me."
Su Qing felt that Ji Shuisheng would be very happy to know about the existence of the coal mine, so she took him to the location where Ji Xiaoying had discovered the coal.
Ji Shuisheng followed behind Su Qing curiously, wondering what she wanted him to see.
"Shuisheng, look at this. It's called coal. It has a lot of heat and burns for a long time. It's better than charcoal and wood. We can pick it up and use it for our fire. We can also sell it to Tartan to make money."
Su Qing showed the coal to Ji Shuisheng. Ji Shuisheng took the black stone and grabbed it. It was pretty black and dirty. It was softer than ordinary stones. With his strength, he could crush it with a little force. He suspected that this unremarkable stone could be used for warmth.
"Can this be burned?"
"Sure. Let's find a cave to rest in tonight. Then, I'll show you how to use this to keep warm."