What brought an end to the qin dynasty? the death of emperor qin shihuangdi the construction of the great wall the decrease in trade and agricultural production the creation of roads and irrigation systems

You have been tasked with sorting the rock samples shown into three categories, with two rocks in each category. what attribute would you use to sort these rocks? which rocks would be in each category? rocks: obsidian, coquina limestone, granite, soapstone,pumice, and gneiss.