khan academy，cmn.khanacademy.org，国外特色，art，computer programming，economics，physics，chemistry，biology，medicine，finance，history，and more. Khan Academy is a nonprofit with the mission of providing a free，world，class education for anyone，anywhere.
信息来源于网络，随着时间的推移，真实性可能会有所变动，敬请认真识别。
