题目

—You look much better. ________ is it that has made you ________ you are today? —Perhaps the special medicine and my family's care. A．What; that  B．That; that C．What; what     D．What; which   答案：：C  6．下列关于电解质溶液的叙述正确的是（　　）A．常温下，在NH4Cl溶液中离子浓度大小顺序为c（Cl-）＞c（NH4+）＞c（H+）＞c（OH-）B．将pH=4的醋酸溶液稀释后，溶液中所有离子的浓度均降低C．中和pH与体积均相同的盐酸和醋酸溶液，消耗NaOH的物质的量相同D．常温下，同浓度的Na2S与NaHS溶液相比，Na2S溶液的pH小