课程目录：
├──normal 10video（480×360）.mp4 18.74M
├──normal 11video.mp4 29.91M
├──normal 12video.mp4 27.70M
├──normal 13video.mp4 18.30M
├──normal 5video.mp4 26.74M
├──normal 6video.mp4 24.87M
├──normal 7video.mp4 30.42M
├──normal 8video.mp4 27.71M
├──normal 9video.mp4 23.42M
├──normal video1.mp4 56.10M
├──normal video3.mp4 23.70M
├──normal14 video.mp4 19.02M
├──normal2video.mp4 29.75M
└──normal4 video.mp4 31.51M
