第三周今天星期一E-textbooksBig schoolbags have been a serious problem for students for a long time. Maybe your schoolbags is too 1 to carry, and it troubles you a lot 2 you want to find a book out to read. Now an e-textbook will 3 you.It is said that e-textbooks are going to be 4 in Chinese middle schools. An e-textbook, in fact, is a small 5 for students. It is much 6 than a usual schoolbag and easy to carry. Though it is as small as a book, it can 7 all the materials（材料）for stu
