已知双曲线方程$C$:$\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$$\left(b>a>0\right)$的离心率为$e_1$，其实轴与虚轴的四个顶点和椭圆G的四个顶点重合，椭圆G的离心率为$e_2$，一定有（    ）

填空。

①You mustn't walk around during landing. ____   A. On a bus

②You mustn't talk to the driver.____         B. On a train

③You must wear a helmet .____          C. On a bike

④You must wear a seatbelt.____           D. On a car

⑤You mustn't put your head out of the window.____   E. On a plane

⑥You must wear a lifejacket.____       F. On a boat

— What a nice dress! It fits you well.
— Thank you. It ______ me seven hundred yuan. I like its design.