—Would you like to see the film Rush Hour (《尖峰时刻》) with me?

—_____[ ]

A. Yes, please.

B. That's a good idea.

C. You're welcome.

D. That's OK.

光线以30°的入射角从某种介质中射向空气时，反射光线与折射光线垂直，求介质的折射率及光在介质中的传播速度。