While the man ____ (run) back home, he saw a dog by the side of the road.
解决问题。
已知双曲线x2a2-y2b2=1a>0,b>0的两个焦点恰为椭圆x24+y2=1的两个顶点,且离心率为2,则该双曲线的标准方程为( )