Last month the manager（经理） of a jewelry shop ( 珠宝店) received a letter. As he was very busy then, the letter lay on his desk till tea-time. He opened it and a 10-pound note(票 ) fell out onto the desk. Within the note was a letter which said:
Dear sir:
    In 1935 I got engaged(订婚 ). But unfortunately I lost my job. At the time a lot of people were out of work. Six months later I got a job again, but of course I was very short of money. I came to your shop to buy a wedding ring(婚戒 ). The assistant took out some rings for me to look at, but she was called away for a moment, and I put one of the rings in my pocket. When she came back, I said I didn’t know the size of my girl’s finger. So I left the shop without buying a ring. My wife died a short while ago and the fact that I never paid for the ring has been heavy in my heart all these years. At that time, the ring cost 2 pounds so I think it is 10 pounds at today’s price and I’m sending 10 pounds.
Yours truly,
A customer (顾客 )

       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.

       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.