题目

下列结构示意图表示的粒子中，属于离子的是A. B. C. D. 答案：【答案】C【解析】C中质子数=11，核外电子数=10，质子数＞核外电子数，为阳离子，故选C。 — Why do you still stay at home? — The meeting has been ________ till tomorrow because of the bad weather. A. put on              B. put off              C. put away                 D. put out