题目

We will be shown around the city:schools，museums，and some other places, ________ other visitors seldom go. A. what           B. which      C.where      D. when   答案：C   能大量共存且形成无色溶液的一组离子是 A．Ba2＋、SO42－、H＋、Cl— B．Na＋、NH4＋、SO42－、OH－C．Ca2＋、NO3－、CO32－、Na＋ D．Na＋、K＋、NO3－、NH4＋