Homework, Videos.

http://www.youtube.com/watch?v=tg00YEETFzg&ob=av2e

http://www.youtube.com/watch?v=CdXesX6mYUE

http://www.youtube.com/watch?v=G2fOum_KWQU&feature=g-music&list=MGGB&context=G22e8911YMAAAAAAAEAA