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.

    Can you imagine astronauts' everyday life in space? They also need to eat,  1 , exercise and relax. They do the same things as us, but they do2 differently.

    On Earth, we put food on a plate and water in a glass. Gravity(重力) holds the food down and keeps the water in the glass.  3 there is almost no gravity in space, so food can float(漂浮) away, and astronauts must eat and drink4  .

    Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a 5bag. They tie the bag to a wall 6 they won't float away at night. Exercise is very important in space. On Earth, your legs 7 your body, but in space, astronauts float. So they do not use their legs often. This is very  8their legs, so they must exercise for thirty minutes every day.

    After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families  9  the radio. Sometimes they just enjoy 10 in the air.

    BEIJING—The sky is gray and air smells strange．It's another day of smog．On Saturday，heavy haze (霾) still covered north and east China．Highways were closed and1 couldn't take off on time．

    The smoggy weather 2 the country's land from north to south，including Beijing, Hebei， Shandong，and 60ther provinces．People could only see clearly 3 than 50 meters in some areas．

    Cities 4 Shanghai and Nanjing have been covered by the gray sky for the past several days．Many walkers in the street had to wear 5 ． In the Lukou airport in Nanjing more than 60 flights were canceled on Saturday 6 the haze，which also made primary and middle schools and kindergartens stop 7on Thursday and Friday in Nanjing．

    The office worker of Environmental Protection said earlier this week that there were several 8 reasons behind the widespread haze：unpleasant weather conditions making9 difficult for smog to disappear，automobile exhaust(尾气)，and coal use for winter heating．

    To fight pollution，the Chinese government now plans to clean up the air by cutting coal use，10 some factories，and removing 6 million old cars from the roads．

     “We must face up to the facts，”said Yan Naiqiang，a professor of environmental science at Shanghai Jiao Tong University．“The treatment of smog will be a long fight． From now on，if we use buses or cars less and do more tidin9，we believe a clear sky is not a faraway dream．”

    The universe is really mystical(神秘的）.Scientists have done lots of study about it but there is still much they haven't discovered.

    Scientists think that there1life on the earth for hundreds of millions of years. However, we have not found life on any other planets2.

    There are eight planets going around the sun. The earth is one of them. There are humans, animals, and many other kinds of life on the earth. There is water and air, too. And compared to other planets, the earth is not too3or too cold. None of seven other planets has an environment like that of the earth.

    The sun and its planets are called the solar system, and our solar system is a small part of a4larger group of stars and planets, called the Galaxy or the Milky Way. There are5stars in the Galaxy, and our sun is only one of them.

    Scientists have also discovered many other galaxy in the universe. They are very far away and their light has to travel for many years to reach us. So 6is the universe? It is impossible to imagine.

    Scientists have sent spaceships to the planet Mars to7photos. They have even sent spaceships to travel outside 8 .However, no spaceship has traveled9to reach other stars in our Galaxy.

    When we see stars twinkling(闪耀）in the sky at night, we may think a lot:10so many stars in the universe, are we alone, or is there life out there in space? Have there been visitors to the earth from other planets? Why has no one communicated with us? We do not know the answer...

    A great way to limit(限制) your impact(影响) on the planet is to follow other animals' way of eating. Squirrels（松鼠）, 1, eat nuts close to their tree houses. Elephants eat trees or plants that 2 around. What these animals are doing is eating in season and locally. We can do the same.

    Most of our favourite fruit and vegetables have their own natural seasons. Modern farming techniques make it 3 for us to eat all kinds of things any time of the year. However, 4 we eat our food in their natural seasons, we will save more energy.

    Eating locally means eating things that are grown close to your home. It will lower the impact that you and your eating 5 have on the environment. An easy way to 6 local produce is to shop at a nearby farmer's market.

    One of the best things you can do is to grow your own food. It may seem like a lot of 7but people and communities all over the country grow some or all of their own food.

    There are many 8 to grow your own food. By doing this, you can 9 where your food comes from. Besides, you can make sure that your food is fresher. It can 10 weeks for the food to get from the farm to the supermarket.

    By growing your own food, those weeks become just days, hours or even seconds. Now that's fresh!