题目

下列各组材料中，不能组成原电池的是 ABCD 电极材料Zn片、石墨Cu片、Ag片Cu片、Zn片Fe片、Cu片 插入的溶液H2SO4溶液AgNO3溶液蔗糖溶液稀盐酸   答案：C解析:构成原电池的条件是活泼性不同的金属或金属和非金属，导线相连并插入电解质溶液中。C中蔗糖不是电解质，不能构成原电池，所以答案选C。 听下面一段对话，回答1-2题。 1. What's wrong with David? [     ]A. He has no time to play computer games.B. He can't understand his mother. C. He has problems with his Math homework. 2. Why does he have such a problem? [     ]A. Because his teacher is not good at all. B. Because he spends too much time on computer games. C. Because he doesn't like Math at all.