They just don't recognize it because it isn't in their traditional textbooks.

他们听不懂这句话，因为这句话在传统的课本中是没有的。

youdao

I think one of the things my teacher did very well was to get away from traditional textbooks as soon as possible.

我认为，我的老师做得很好的一点就是尽早地摆脱传统的课本。

youdao

Some key benefits over traditional textbooks include: wider distribution, lower costs, teacher recommendations and customizable texts.

相对于传统的教科书，这样做有如下一些主要的好处：传播更广，成本更低，老师的推荐以及可对教材内容进行定制。

youdao

California approves traditional textbooks in six-year cycles.

VOA: special.2009.08.27

The original idea was to use the iPads as e-readers, in place of traditional textbooks.

FORBES: Pros And Cons Of iPads In The Classroom

Reitzes also noted that iPads and iBooks textbooks will be an easier sell to college students who will benefit more from the cost savings over traditional textbooks.

FORBES: How Will Teachers Pay For Apple's New iBooks? Sites Like DonorsChoose.Org

Steve Jobs had a dream of making traditional textbooks obsolete.

FORBES: Steve Jobs' School House Dream Comes To Fruition But Not Big News For Stock