She is a nice girl. _____________ is why I like her. [ ]
A. Which
B. That
C. What
D. It
答案:B
已知双曲线C1:2x2-y2=8,双曲线C2满足:①C1与C2有相同的渐近线,②C2的焦距是C1的焦距的两倍,③C2的焦点在y轴上,则C2的方程是______.
偏瘫