If the only sports you do are dancing your fingers across your keyboard, you could be in serious danger of more than just becoming overweight and out of shape. Do you often feel sleepy, like something is weighing down on your head? Do you feel forgetful? Do you sometimes feel uncomfortable up and down your neck and lower back, and you can't explain why? Do you get sick often? It could be radiation   from your computer causing it. If you spend three hours or more a day in front of a computer (and at this point, who doesn't?), you are more easily harmed by the _ . We have got so used to using computers that we often neglect   to think of them as dangerous sources of harmful radiation. A safe amount of radiation is 25 V/m (Volts/meter). Do you want to guess how much our personal computers give off? Keyboard: 1000 V/m Mouse: 450 V/m Monitor: 218V/m CPU: 170V/m Notebook computers: 2,500 V/m Ways of Protect Yourself from Harmful Computer Radiation 1. Decorate your desk with cactus   plants, they take in radiation. 2. Drink two to three cups of green tea a day and eat an orange daily. The vitamins in tea leaves and oranges protect us from radiation and keep our eyes healthy as well. 3. Use a screen filter  for your monitor. 4. Avoid having metal objects   nearby on your desk. 5. Put the back of the computer to the wall. Most of the radiation comes off the back. 6. Keep your monitor at least 50cm away from your face. 7. Keep your computer rooms ventilated  . 8. Eat healthily-----especially fruits and vegetables. 9. Don't fall asleep on your computer. Turn it off if you have to rest nearby. The ways above are useful, why not have a try at once? The best title of the passage is  _  .
Computer problems Computer radiation: a silent killer Protect yourself Harmful radiation