题目

______ all day, he was terribly hungry. A. Having not eaten                 B. Eating nothing   C. Not having eaten                 D. Nothing having eaten 答案：C 将盛有12 mL　NO2和O2混合气体的量筒倒立于水槽中，充分反应后，还剩余2 mL无色气体，则原混合气体中O2的体积是 A． 1.2 mL B． 2.4 mL C． 3.6 mL D． 4 mL