已知F 1 、F 2 分别是椭圆 x 2 a 2 + y 2 b 2 =1(a>0,b>0) 的左、右焦点,其左准线与x轴相交于点N,并且满足, F 1 F 2 =2 N F 1 ,| F 1 F 2 |=2 . (1)求此椭圆的方程; (2)设A、B是这个椭圆上的两点,并且满足 NA =λ NB ,当 λ∈[ 1 5 , 1 3 ] 时,求直线AB的斜率的取值范围.
【单选题】请阅读Passage l,完成第21-25题。 Passage 1 When asked by Conan if his daughters had smart phones, comedian Louis CK explained that he had successfully fended them off by simply replying, 'No, you can' t have i...
A.
CK was a good father and a very brave comedian in her eyes.
B.
CK didn't agree to buy smart phones for his young daughters.
C.
She was very impressed by his solution to the smart phone probletn.
D.
She was encouraged by him not to make any compromises to her daughter.