三角形个数的规律公式图片简介：At this time, the chubby shopkeeper Liu came out with a smile on his face, "I'm sorry, you three, this shop is closed, many people came to see me." He didn't greet me immediately, which was a bit neglectful.
At this time, the chubby shopkeeper Liu came out with a smile on his face, "I'm sorry, you three, this shop is closed, many people came to see me." He didn't greet me immediately, which was a bit neglectful.
