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Big schoolbags have been a serious problem for students for a long time.Maybe your schoolbag 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 study.The students can read the text page by page on the 　8　，take notes with the pointer（屏写笔）.Or even “　9　” their homework to their teachers by sending e-mails.All they have to do is to press a button.　　

Some people say e-textbooks are good，but some say they may be 　10 　 for the students’ eyes.What do you think of it?

Big schoolbags have been a big problem for students for a long time. Maybe your schoolbag is too   1   to carry, and it troubles you a lot   2  you want to find out a book to read. Now e-textbooks will   3  you.

It is said that many Chinese middle schools are going to use e-textbooks. An e-textbook, in fact, is a small   4  for students. It is much   5  than a usual schoolbag and easy to carry. Though it is as small as a book, it can   6  everything for study. The students can read the text page by page on the   7  ，take notes   8  the pointer (屏写笔)，or even “hand in” their   9      to their teachers by sending e-mails. All they have to do is to press a button (按开关).

Some people say e-textbooks are good, but some say they may be   10  for the students’ eyes. What do you think of it?

Big schoolbags have been a big problem for students for a long time. Maybe your schoolbag is too 31 to carry, and it troubles you a lot 32you want to find out a book to read. Now e -textbooks will 33you.

 It is said that many Chinese middle schools are going to use e - textbooks. An e - textbook, in fact, is a small 34for students. It is much lighter than a usual schoolbag and 35to carry. Though it is as 36 as a book, it can hold (容纳) everything for study. The students can read the text page by page on the 37 , take notes 38the pointer (屏写笔) ,or even "hand in" their 39to their teachers by sending e - mails. All they have to do is to press a button ( 按开关).

Some people say e- textbooks are good, but some say they may be40for the students' eyes. What do you think of it.?

1.A. expensive   B. heavy   C. light

2.A. till   B. after  C. when

3.A. trouble   B. help   C. solve

4.A. TV  B. radio  C. computer

5.A. easy   B. difficult  C. hard

6.A. smaller   B. small  C. harmful

7.A. paper   B. keyboard   C. screen

8.A. with  B. in   C. by

9.A. computer  B. homework  C. e - textbooks

10.A. bad   B. dangerous  C. good

 Computers can injure(伤害) you. Most other injuries happen suddenly. For example, if you    a bike and break your arms, it happens very    . But computer injuries slowly.You probably know how to ride a bike safely. Now learn to     a computer safely.
Your eyes
   light can injure your eyes,     never sit too close to a computer screen. Your eyes should be    50 centimeters（厘米）    the screen（平幕），  Remember to look away from it sometimes. This gives your eyes a rest.
When you use a computer, the window    be on your left or your right. If it is behind you, the light will reflect on (反射) the screen. If the window is in front of you, the sun and the screen will     shine into your eyes.
Your hands and wrists (手腕)
Hand and wrist injuries can happen because the hands and wrists are moved in the same way     times. If you use a keyboard for a long time,      these three rules: 1) Rest your wrists on something. 2) Keep your elbows at the same height as the keyboard. 3) Stop something and exercise your hands, wrists and fingers in a different way.
Your back
Some people sit for many hours in front of a computer. If you sit in the wrong way, you can injure your back or your neck. So you should sit with your back straight. The top part of the screen should all be in front of your eyes. Your forearms, wrists, hands and the upper part of your legs should all be parallel (平行) to the floor. If you are sitting for a long time, get up      30 minutes and      your arms, legs and necks.
   your computer, but use it safely.