有一网站---Khan Academy,a not-for-profit educational organization,created by Salman Khan in 2006.大家可以去看一下网站。他的背境很有意思。他高中第一名毕业,进入MIT, a BS in mathematics, and a BS in EE and computer science in four years,(the most difficult two major in MIT ).a MBA from Harvard Business School. You can see that he is a very smart and very thoughtful person. So you can really trust his knowledge for K-12 and another subject.你看他很有头脑,发挥自己所长。2009 他得到Micorosoft reward for 1.5M. , 2010 他得到Google reward for 2M.,还有 许多donations. 共有2400个 videos.供观看。讲的很清楚。你能看出他真的有passion and ability ,not for money.He really likes what he does.That's why he is recognized by so many famous people and big company and lots of teacher,parents and school in the world.I think that he really knows how to teach. A super man!