We ______ the difficulty together, but why didn’t you tell me? A. should face B. might face C. could have faced D. must have faced 答案:C从理论上讲,Li是很活泼的金属,与水反应应当很剧烈。但事实上反应却是开始较快,一会儿就迅速缓慢起来。其原因主要是 ( )
A.Li的密度很小,浮在水面之上
B.生成物LiOH溶解度较小,附着在Li表面
C.反应开始放热而使速率变慢
D.反应产物对此反应有催化作用