— My teacher says she's cancelling the class play. I just can't understand.

— ______.You were looking forward to it. [ ]

A. It doesn't matter

B. It's very unwise of her

C. Don't worry about it

D. You must be disappointed

美丽的城市广场中，有一个美妙的音乐喷泉．在水池的底部射出的光柱会伴随着动听的音乐，将喷泉照射得绚丽多彩．某一时刻，一束光柱从池底通过水面斜射向空气，在水面上发生了光的反射和折射现象．若入射角为30°，则反射角为______；当入射光线远离水面时，折射光线将______水面．