题目

All his hopes were d(破灭) by the terrible accident. 答案：【1】destroyed下列关于氯水的叙述,正确的是 A．新制氯水中只含Cl2和H2O分子      B．新制氯水可使蓝色石蕊试纸先变红后褪色 C．光照氯水有气泡逸出,该气体是Cl2    D．氯水放置数天后pH值将变小