Computers can injure you. Most other injuries happen suddenly. For example, if you fall off a bike and break your arms, it happens very quickly. But computer injuries slowly.
　 You probably know how to ride a bike safely. Now learn to use a computer safely.
Your eyes
　 Too much light can injure your eyes, so never sit too close to a computer screen. Your eyes should be at least 50 centimeters from the screen. Remember to look away from it sometimes. This gives your eyes a rest.
　 When you use a computer, the window should 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 both 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 hundreds of times. If you use a keyboard for a long time, follow these three rules: 1) Rest your wrists on something. 2) Keep your elbows (肘部） 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（前臂）, wrists, hands and the upper（上部） part of your legs should all be parallel (平行) to the floor. If you are sitting for a long time, get up every 30 minutes and exercise your arms, legs and necks.
　 Enjoy your computer, but use it safely.
【小题1】A computer screen may injure your eyes if __________.

People in different countries have different ways of doing things. Something　is  1  in one country, but  it may be quite impolite in another. In Britain, you mustn`t lift your bowl to your    2    when you are having some liquid(液体)food. But it’s     3   in China.  And  in  Japan you even needn`t worry  about making   4    while you are having it . It shows that you`re enjoying it . But people in Britain think it is bad manners . If you are a visitor in Mongolia ,what manners do they wish    5  to have ? They wish you to have a loud“burp”( 打嗝)     6     you finish eating .Burping shows that you like the food .
In  Britain , you should  try not   to   7  your  hands on  the table when you’re having a meal .But in Arab (阿拉伯)countries you must be very careful with your hands . You   8    eat with your left hand .Arabs consider (认为)it very    9   manners eating with left hands .So when you are in other countries ,   10    carefully and follow them .As a saying goes , “Do as the Romans do .”

Mr. Black was working in a factory in a big town. He liked 　1　 very much, and was very good　2　 it. When he was free, he　3　 down to a small river behind the factory and tried 　4　 some fish, but there were very few there, 　5　 the water wasn’t clean. One summer he went to the seaside during his holiday and stayed at a small cheap hotel.
“I have never fished in the 　6　 before.” He thought. “It will be more interesting than fishing in our river.”
　7　 first he caught a lot of fish and was very 　8　 . He gave them to the hotel and they cooked them for guests, and he enjoyed himself very much. After　9　, he did this every day. But 　10　 he got his bill(账单) at the end of the week, he saw it, “For oil（油） to cook fish(7 days), 70 dollars（美元）.”