题目

下列电子式中书写错误的是 (    ) A.                       B. C.                    D. 答案：BD 解析:判断电子式正误首先要从判断物质种类入手，是离子化合物、共价化合物还是单质或离子。—When were you born?—I was born ________August lst, 1994.     [     ]A. in    B. at    C. on