题目

 ____they were hungry and tired, ____they still kept on searching for the missing child. A. Because；so                                                B. Because；不填         C. Although；but                                             D. Although；不填 答案：D在溶液中能大量共存的离子组是（ ）A．Al3+、Cl-、Ca2+B．Mg2+、SO42-、OH-C．Na+、SO32-、H+D．Fe3+、SCN-、K+