When Springfield High School in Palo Alto，California invited Khan to speak in person－he immediately connected to the students there.

　　The idea of short lessons that can be played over and over again attracted high school senior Bridget Meaney.She said she had trouble with math in the seventh grade.“I think the teachers are good，but they can't teach at a speed that's perfect for everyone，”she said.“I like the idea of learning something in class but then going back and pressing pause or rewind and actually getting a deeper understanding of it.”

　　Originally，Khan kept his lessons short because of YouTube restrictions.Now，he thinks short_is_better.“Education researchers now tell me that 10 minutes is how long someone can have a high level of concentration.And anything beyond that and your brain switches off，”he said.

　　For Khan，teaching math，science，and finance is just the beginning.He says he's ready to expand his YouTube site to include other subjects as well.

　　【语篇解读】 加利福尼亚一个财务分析师放弃自己的工作，而从事一个没有报酬的工作——在网络上教授数学，结果很受欢迎……

　　43．What gave Khan the idea of teaching math online?

　　A．His success in helping his cousin learn math.

　　B．His discovery that many students found learning math difficult.

【2017届高考英语（重庆专用）二轮精练：选修9 unit2 Sailing the oceans单元测试】相关文章：

★ 【北京专用】2014届高考英语一轮复习方案课时作业：必修1 Unit 3 Travel journal

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修3 unit3《The Million Pound Bank Note》

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修2 unit5《Music》

★ 【三维设计】2017届高考英语（江苏专用）二轮复习课件：必修3 Unit 1《The world of our senses》

★ 【课堂新坐标】2017届高考英语（通用版）二轮复习短文改错专题训练：训练2 短文改错（Ⅱ）（含解析）

★ 2014高考英语（新人教版）一轮基础训练（8）A、B卷（附答案或解析）

★ 【三维设计】2017届高考英语（江苏专用）二轮复习素材：高考写作6类背诵宝典 1.书面表达常用词汇

★ 【三维设计】2017版（江苏专用）二轮复习练习：选修8 Unit 4《Films and film events》课时跟踪检测A卷（含解析）

★ 2014高考英语（新人教版）一轮基础训练（9）A、B卷（附答案或解析）

★ 2014高考英语（新人教版）一轮基础训练（4）A、B卷（附答案或解析）