题目

点P(-3,1)在椭圆=1(a＞b＞0)的左准线上,过点P且方向为a=(2,-5)的光线经直线y=-2反射后通过椭圆的左焦点,则这个椭圆的离心率为(    )A.       B.       C.      D. 答案：答案：A解析:如图所示,入射光线PM所在的直线方程为y-1=-(x+3),即5x+2y+13=0.令y=-2,得x=-,即M(-,-2).反射光线MF所在的直线方程为y+2=(x+).∵F(-c,0)在直线MF上,∴0+2=(-c+),c=1.又∵点P(-3,1)在椭圆的左准线上,∴-=-3.∴a=,e=.阅读理解。     People’s Park is a good place to have fun. It’s a very busy and clean park. Every day many people have fun there, including(包括) the old, the young and children. There are many kinds of flowers, grass and trees in it. If you go there in the morning, you can listen to the birds singing. If you go there in the evening, you can see many beautiful lights. Where is it? You can take No. 1 bus there. It’s on Zhongshan Road on the right. It’s next to a bookstore, and you can find many good books there. Near the park is a big cinema. You can also go to the movies with your friends.根据短文内容完成下列信息。▲ People’s Park is a busy and     1     park.▲ There are many flowers, grass and     2     in the park.▲ If you got to the park in the      3    , you can listen to the birds singing.▲ You can take No. 1     4     to get to the park.▲ There is a big     5     near the park.