An e-books (also referred to as an electronic book， e-books，or e-book. is a digital version (版本). of a print book that you download and read. But if you want to read an e-books, you must have an e-books Reader, which is a kind of free software used by your computer. Make sure you have installed the appropriate Reader before you download your e-books from the Internet. The software allows you to turn the words on the screen into the size you like. It also helps you turn pages and change your viewing options (计算机屏幕上的阅读选择). E-books are a fun alternative to regular books. You can download them to any computers and create your own library of hundreds of titles. If you load them onto your portable computer，you can take them with you when you travel. Some E-books are even interactive! Best of all，when you order an e-books，there is no waiting and no shipping charges. The amount of time it takes to download your e-books depends on the speed of your connection and the size of your e-books.
The passage is mainly about _____.

A.a better way to download an e-Book

B.a new kind of book the e-Books

C.the new version of e-Books

D.the fun of reading e-Books