We all need a healthy environment, but we produce waste every day and it does harm to our environment. Though we are young, we can still do something to help. In fact, even the simplest everyday activities can make a real difference to the environment. Here are some ideas for you to live a green life.
   Remember these three words: reduce, reuse and recycle. Reduce means “use less”. Don't waste things. This saves money and reduces pollution and waste going into the environment. Before we buy something new, think if it is really necessary or maybe the old one will be just as good! When we do buy things, choose local products if possible, and try not to buy too many things from abroad.
   Reuse means “use again”. Use things for as long as possible. When we buy things, make sure that they last a long time. We should take care of them so that they will last, and we should repair them if we can instead of throwing them away and buying new ones. Don't use a paper cup or a paper bag. It's better to use a china cup and a lunch box because you can use them again.
   Recycle means “change things into something else”. Although it takes energy to change something into something else, it's better than throwing things away or burning them. Find out what can be recycled in your neighbourhood and take part in recycling programmes. We should also buy products made from recycled materials, such as recycled paper, to help save trees.
Title:{#blank#}1{#/blank#}to Live a Green Life

    Every object has weight. But the center of its weight is not always in the middle of the object. If the top of an object is heavier than its bottom, it will fall over easily. We say that its center of gravity is high. But if the bottom is heavier, it won't fall easily. Then we say that its center of gravity is low.
    Look at the first picture. This empty box must fall over, because its center of gravity (C) is not above the line of its bottom (AB).
Now look at the second picture. There is some heavy iron in the bottom of this box. It will not fall, because its center of gravity is above its bottom.

                                                                                          B

    Have you ever wondered how and why a fall leaf changes color? We first have to understand what leaves are and what they do.

    Plants are the world's food factories. Plants take water from the ground and take CO₂ from the air. Plants use sunlight to turn water and CO₂ into glucose(葡萄糖). Glucose is a kind of sugar. Using it as food, plants get energy and grow. Plants using sunlight to turn water and CO₂ into sugar is called photosynthesis(光合作用). ChlorophyII helps photosynthesis. It gives plants their green color.

    As summer ends and autumn comes, the days get shorter and shorter, and trees "know" to begin getting ready for winter. During winter, there is not enough light or water for photosynthesis. Trees rest during this time and live on the food they store during the summer. They begin to shut down their food — making factories. As the green chlorophyII disappears from the leaves, we begin to see yellow and orange leaves. These colors have been in the leaves all the time. We just can't see them in the summer, because they are covered up by the green chlorophyII.

    The bright reds and purples we see in leaves are made mostly in autumn. In some trees, glucose is caught in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn turn this glucose into a red color. The brown color of trees is made from waste left in the leaves. It is mixture(混合物) of all these things. It makes the beautiful leaves during autumn.

    In 1969, humans landed on the moon for the first time. Now, many other countries want to go there as well. Why?

    The moon has a lot of minerals (矿物质) and other useful things. We want to find out if we can use them. The moon is our closest neighbor in space. We can use it as a rest station. Then, we can learn more about other planets far away in space.

    The moon is 3,474 kilometers in diameter (直径). It is about one-fourth the size of Earth. If Earth is the size of a basketball, the moon is the size of a tennis ball.

    The moon has much less gravity than Earth. If you can jump 1.5 meters on Earth, you can jump 9 meters on the moon.

    The moon is very quiet. There is no sound there. There are a lot of grey rocks on it. The moon's sky is always black.

    Our moon is about 384,400 kilometers away from Earth. The total length of the Great Wall is about 21,200 kilometers. We would have to put about ____ Great Walls end to end to reach the moon!

    How much sleep do we need? We are all different. Some people need only three hours of sleep a night. Others need ten hours of sleep a night. Most Americans sleep an average(平均) of seven to eight hours a night. After the age of fifty, the average sleeping time goes down to 6.5 hours a night.

    Most people have a bad night when they cannot fall asleep(睡着). The name of this problem is called insomnia.

    This isn't a new problem .Many famous people in history had insomnia .Some of these people had special ideas to make them sleep .Benjamin Franklin, the famous inventor had four beds. He moved from one to another to fall asleep .King Louis XIV(国王路易十四)of France had four hundred and thirteen beds and hoped to fall asleep in one of them .Mark Twain, the famous American writer, had a different way. He lay on his side across the end of his bed.

Is It Better to Read Books or Listen to Them?

    We often think how fast we learn something depends on how smart we are. If your brain is taking in material quickly, you're clever; if not, well, that doesn't say great things about your IQ. But science shows context (上下文) and technique (技术) actually play a big role in how fast we learn, and even small changes – like the way you use to read – can make a big difference.

    Audio (音频的) books have plenty of advantages: you can enjoy them anywhere, even in the car, and not printing books saves trees. Poor readers also often find them more interesting. But according to the latest research, if your goal isn't to pass the time in traffic, but instead to learn something difficult, you should choose a physical book.

    In a recent opinion piece in the New York Times, psychology (心理学) professor Daniel T.

    Willingham mentioned a 2010 study where 48 students either read or listened to an article about child psychology. Although the students spent the same amount of time with their material and did about the same number of distracting (分散注意力) activities while they absorbed the information, they scored very differently on a 10-item quiz later. Generally, the readers scored 81 percent but while the listeners scored 59 percent. Why does listening vs reading material have such a great effect on learning?

    Willingham explains that first, most of us read more slowly than we listen (especially when pausing and rereading), and when you're trying to absorb new information, slower seems to be better. "About 10 to 15 percent of eye movements during reading are actually regressive – meaning the eyes are going back and re-checking," he explains to TIME. "This happens very quickly…"

    Second, books offer visual cues (可视线索) that help our brains organize and understand new information. Things like chapter breaks, subheadings, and lists help us in making sense of the material and understanding how it fits together. You lose all that when you go the audio way.

    The bottom line is simple: Don't feel shame about passing your time in traffic with an audio book. However, be aware of audio's limitations when it comes to studying, and seriously consider choosing good old-fashioned reading instead.