Our factories and homes burn coal and oil. Every year we have forest fires somewhere. Many scientists believe that the weather is changing.

      The earth will perhaps be warmed by about 7℃ at the South Pole(极) and the North Pole. The ice will be melt(融化). The sea level(平面) will rise by about 7 meters. As a result, water will cover cities like London, Tokyo and New York. Some ports(港口) and towns along the coasts will disappear under water.

      Some other scientists think that the dust, smoke and pollution from coal, wood and oil fires will block out(封闭) the ultraviolet rays(紫外线). Then the earth will become colder and great sheets of ice will cover Europe and North America.

      When chemicals in the air mix with rain, we have acid(酸) rain. Acid rain can bring us great harm. It destroys(破坏) forests and kills life in lakes and rivers.

      People are beginning to see how serious the problem is. They find it important to work with nature instead of against it. They are trying to save the earth in many different ways. But one of the most important things to do is to make people understand that saving the earth is saving ourselves.

    How do you light up the night sky? The answer is by using electricity. But did you know that nature can glow (发光), too?

    Scientists have found many glowing living things. Most of them live in the ocean. Some use their lights to talk to each other. Others use them to hunt, to mate (交配) or to protect themselves. The vampire squid (幽灵蛸), for example, uses a cloud of light to scare enemies.

    Scientists around the world are looking at this kind of light for new ideas. In 2013, the US company Gleaux said it has created the world's first light-producing plant, the Daily Mail reported. It is a genetically-modified (转基因的) plant. It can glow like a firefly.

    Alexander Krichevsky, the company's founder (创始人), and other scientists hope that in the future, glowing plants could replace lamps and glowing trees could light up highways. Krichevsky also hopes the technology could be used in farming. Farmers could know when their crops need water or are ready to be picked if they glow.

    While Gleaux is working on glowing plants, the French company Glowee is trying to use glowing bacteria (细菌) to light up shop windows and street signs. It's the same type of bacteria that cause a type of squid to light up, New Scientist Online reported.

    "Our goal is to change the way we produce and use light," said Glowee founder Sandra Rey. "We want to help reduce the 19 percent of electricity consumption (消耗量) that is used to produce light.

    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."