题目

河北省衡水中学2011年第二学期第一次调研考试 I was much impressed by the great changes and fast pace of life in Shanghai ______ I came to visit this fantastic city.    A. at the first time     B. for the first time    C. by the first time     D. the first time 答案：D已知椭圆的两个焦点和短轴的两个端点恰好为一个正方形的四个顶点,则该椭圆的离心率为（   ）A．B．C．D．