预习案 一、话题导入阅读 a future without text books the way students gather information is changing rapidly but textbooks are not. they are heavier than ever, and students can`t sell them back to the bookstore. it seems reasonable to suppose that the future of textbooks will look rather different, if they exist at all. paul bierman, a university professor in america, has thought a lot about the future of the textbooks. at the same time, in order to prove his idea, he has been rewriting a part of a standard textbook on environmental geology. in an era when students can open up their laptops and search the web for all kinds of information, there is no longer any need for heavy textbooks. he considered the future of textbooks when he organized a
