题型:判断题 —_____ I finish the book this week?—No, you ____ . You ____ return it to me the week after nextA.Need; mustn’t; mustB.Should; shouldn’t; mayC.Mus; needn’t; canD.Can; don’t have to; must 查看答案
题型:判断题 有10 g不纯CaCO3样品与足量盐酸作用后生成4.44 g CO2,且溶液中残留难溶物质。则对于此样品中是否存在①MgCO3;②K2CO3;③SiO2杂质的判断中,正确的是 [ ]A.肯定含①③,不含②B.肯定含①③,可能含② C.肯定含②③,不含① D.肯定含②③,可能含① 查看答案