Everyone knows water is important to all living things. But do you know these interesting 1 about water?

    Without water, the Earth would look 2 the moon. People can live several days without food, but only3days without water. Scientists say 70% of the human body is made up of water. Water 4 up 83% of our blood, 70% of our brain, and 90% of our lungs (肺). About 95% of a tomato is water, and about 80% of an apple is water. So 5 can we do to help with water problems?

   Keep a shower to 10 minutes or 6 time. It helps save much water. Use a broom to sweep the floor, the stair, the garage (车库), or the sidewalk instead of water.

     7 throw your used water away. Instead, you can use some to water plants or run the toilets. Use a bucket (桶) of water to 8 your bike or the  family car instead of water pipes.

     Use water only 9 you need it. Don't leave water running. Be sure to turn the tap 10 when you are not using it.

    Fire can help people in many ways. But it can also be very harmful.

Fire can keep your house 1, give light and cook food. But fire can burn things 2 . Big fire can burn trees, houses, animals and people.

    Nobody knows how people began to use fire.  But there are 3interesting old stories about how a man or a woman started a fire. One is4 a man. The man 5 a very long time ago. He went up to the Sun and 6 fire down.

    Today people know how to make a fire with matches(火柴). Children sometimes 7 to play with them. But matches can be very dangerous. One match can burn a piece of paper, and 8 it can burn a house. A small fire can turn into a big fire very quickly. So you   9 be careful with matches.

    Be careful with fire, and it will 10 you. But if you aren't careful with fire, it may hurt you.

    At the beginning of this century, medical scientists made a interesting discovery(发现). We are bulk not just of flesh (肉)and blood but also of time. They were1to show that we all have a body clock inside us, which controls the2and fall of our body energies. It can 3us different from one day to the next.

    The idea of a body clock should not be too4because the lives of most living things are controlled by the 24-hour-night-and-day cycle. We feel 5 and fall asleep at night and become 6 and energetic during the day. Most people will have a bad feeling 24-hour cycle is 7. For example, people who are not used to working at night can find that luck  (缺少)of sleep causes them to 8 badly at work.

    Besides (除了) the daily cycle of sleeping and waking, we 9 have other cycle which lasts longer than one day. Most of us would 10 that we feel good on some days and not so good on others. Sometimes our ideas seem to be so active, and at other times they are not.

    Saving the environment is actually quite simple, when you come to think about it. It does not have to be a problem. If you and everyone follow these tips, you are helping save the environment easily.

    Switch off the lights when you leave the room. By now you have probably wasted thousands of watts (瓦特) lightening your room 1 you weren't there. If you work on a home office, this habit is not only bad for the environment, but also for your pocket.

    Turn off the computer when possible. If you know that you will be 2 for four hours or more, turning it off could lead to large savings over the long run.

    Print only when necessary. Sure, reading on paper might be more comfortable, but you should avoid printing those two-line e-mails every time. Read it on the screen and print only necessary documents. Remember also to use 3 sides of the sheet.

    Use fluorescent lamps (荧光灯). The fluorescent lamps may 4 more in the stores, but within the time you use one, you should have already recovered the investment. A normal incandescent light bulb (白炽灯泡) lasts 750 hours but a fluorescent bulb will give off the same amount of light yet last for 7,500 to 10, 000 hours with 1/3 of the wattage.

    Use low-flush (冲洗) toilets. In your household, 40% of the pure water is flushed down the toilet. You can 5 this easy way at home; use small plastic bottles, filled with water or stones to displace (置换) the amount of water in toilets. This will make it a "low-flush toilet", or you can use a displacement bag in your tank, which might reduce 1-2 gallons per flush.