题目

图文匹配。⑴ ⑵ ⑶ ⑷ ⑸ A. The girl is shorter than the boy.B. The elephant is stronger than the bird.C. The apple is bigger than the pear.D. The book is heavier than the eraser.E. She has long hair and a small nose. 答案：【1】D【2】B【3】E【4】A【5】C（本题满分15分）已知A(1,1)是椭圆（）上一点,F1­，F2 是椭圆上的两焦点,且满足 .(I)求椭圆方程；(Ⅱ)设C,D是椭圆上任两点,且直线AC,AD的斜率分别为  ,若存在常数 使/，求直线CD的斜率.