题目

Peter, Jim and I ________ classmates. ____all love maths lessons. A . are all, We B . all are, We C . are all, They D . all are, They 答案：A在溶液中能大量共存的离子组是（　　）A．Ca2+、CO3 2-、Cl-B．H+、SO42-、CO32-C．K+、H+、OH-D．Fe3+、Na+、NO3-