Stop reading for a minute and think about what you see when you look up at the sky on a clear night. You probably see many stars (星星). Long long ago, farmers watch some stars to know when to plant their crops. Travelers did so to find their way in the dark. Today stars are still important to some people.

    Scientists find that most stars are very big. In fact some stars are so far away that it would take millions of years to get to them even by spaceship.

    Another thing we know today about stars is that some are made up of(由…组成) hot gases. The gases are so hot that they send out light. If you watch a star carefully, you may notice that it twinkles(闪烁)sometimes. As you may understand, light from a star must shine through the air before you can see the star. Air is always moving, it makes light from the star move back and forth. When the light moves, it makes the star twinkle. Stars also have different colors. The colors of a star depend on how hot it is. To our surprise, the cool stars are red and the hottest stars are white.

    In most parts of the world, many students help their schools make less pollution. They join "environment clubs". In an environment club, people work together to make our environment clean.

    ●No-garbage lunches. How much do you throw away after lunch? Environment clubs ask students to bring their lunches in bags that can be used again. Every week they will choose the classes that make the least garbage and report them to the whole school!

    ●No-car day. On the no-car day, nobody comes to school by car—not the students or not the teachers! Cars give pollution to the air, so remember:

    Walk, jump, bike or run.

    Use your legs! It's lots of fun!

    ●Turn off the water! Did you know that some toilets can waste twenty to forty liters (升) of water an hour? In a year that would fill a small river! In environment clubs, students mend those broken toilets.

    We love our environment. Let's work together to make it clean.

    We all know that many women like to wear dresses. They enjoy many kinds of colourful and popular dresses. But have you ever heard of a 4D dress?

    Jessica Rosenkrantz in the USA used 3D printing technology to make a very special and new dress. It will help with the problems of different styles of women's dresses.

    The dress maker called the special dress a"4D dress" ". It is like the fabric(织物). It can turn into different kinds of shapes.

    The company, in Massachusetts, the USA, also made a smartphone and an app(应用). They can help women to control their dresses. If women use the phone and the app, they can change the colour, the style and many other things of the dresses. Isn't it very interesting?

    When she talked about her work, Jessica said, "There will be many more changeable dresses for women in the future. I am interested in making them too, I can't wait to make different kinds of new dresses for women."

    Some of the greatest problems we face today are the destruction (破坏) of our environment. Brown clouds, polluted water, endangered wild animals…. these problems seem so huge.

    So my family does what we can. We take cloth bags to stores instead of using plastic bags. We walk where we don't have to drive…

    But does it do any good? When I am the only one in line at the market with cloth bags, am I doing any good? Does my walking to stores make any real difference to the world?

    I recently learned something about flamingos(火烈鸟) which like to get together in groups of a thousand or more. Every year, when the time comes for migration(迁徙), a few of them first take off from the lake. But none of the others seem to notice. So the small group returns. However, the next day they try again. This time a few more fly along with them, but most of them still pay no attention, so they return again. They try for several times. Every time a few more birds join in but, since thousands of the others still take no notice, the great migration plan is once more stopped.

    Then one day something changes. The same small group of birds once again starts flying and a small number more join in just as before, then more. Finally, they all take flight and the migration really begins. What a spectacular sight it must be — thousands of flamingos taking off into the sky at once!

    A few can make a difference. Even if you're the one to take the first step, and continue trying, others will someday take notice and together we will solve even our greatest problems.