A salted fishapos;s

Qing bricks cost one copper coin each, and red bricks cost one copper coin each.,He was going to the quarry to see if they also used copper coins for transactions. If so, he would take his silver and exchange it for copper coins first, then use the copper coins to pay, making a profit on the difference.,Someone asked, "Yan Er, are there still many stones like this in the quarry"。