At the sight of the scene, he was almost to death. A. frightening; frightened B. frightened; frightened C. frightening; frightening D. frightened; frightening 答案:A将一定量的乙醇(C2H6O)和氧气置于一个封闭的容器中引燃,测得反应前后各物质的质量如下表:物质乙醇氧气水二氧化碳X反应前质量/g4.68.0000反应后质量/g005.44.4aA.表中a的值为2.6 B. X一定是该反应的催化剂 C. X可能含有氢元素 D.若起始时氧气的质量是9.6g,则无X生成