Do you know fish come out of eggs when they are born? After the little fish comes out of the egg, it eats the food in the egg. When it is big, it leaves the egg. It swims in the water. You can see the eyes and nose. Its ears are hidden in the head.

    Spree fish eat other fish. Some fish have small mouths and teeth and they often eat plants.

    A computer program that could help catch and ever translates from aliens in outer space has been started by a British scientist.

    If aliens are discovered one day, scientists fear their language may make it possible to understand them. But John Elliott of needs Metropolitan University in Britain has come up with a program that can figure out the structure(结构)of their language. He thinks that's the first step in understanding what they are saying.

    Dr. Elliott's program would compare an alien language to a database (数据库)of 60 different languages in the world to look for a similar structure. He believes that even an alien language will have its own structure. Language has to be structured in a certain way, or it will be harder to use, he told New Scientist magazine.

    Research had shown that it is possible to know if a signal(信号)carries a language rather than a picture or music. Dr. Elliott has gone a step further by finding a way to pick out what might be words and sentences. Because languages have different word orders, Dr. Elliott has set up a library of the sentence structures of 60 human languages.

    If a message is received from outer space, it could be compared against this database. Scientist would then be able to see if ti's similar to any human language, or a mix of the language.

    However, Dr. Elliott also said that in order to translate what the aliens are actually saying, it may still be necessary to have a code book.

    In today's world, almost everyone knows that air pollution and water pollution are harmful to people. However, not all the persons know that noise is also a kind of pollution, and that is harmful to human, too.

    People who work and live under noisy conditions usually become deaf(聋的). Today, however, scientists believe that 10 percent (百分比) of workers in Britain are being deafened by the noise where they work. Many of the workers who print newspapers and books, and who weave(织) cloth become deaf. Quite a few people living near airports also become deaf. Recently(近来) it was discovered that many teenagers in America could hear no better than 65-year-old people, for these young people like to listen to "pop" music and most of "pop" music is a kind of noise. Besides(除此之外), noise produced by jet planes or machines will make people's life difficult and unpleasant, or even make people ill or even drive them mad.

    Nowadays the government in many countries have made laws to reduce or control(控制) noise and make it less than 85 decibels(分贝).  In China, the people's government is trying to solve not only air and water pollution problems but also noise pollution problem.

    Thousands of years ago, people couldn't live for long. Most people only lived to be twenty-five or thirty years old. 20% of people died before they were twelvemonths old and another 30% could not live to be five years old.

    Today, people can live much longer. One reason is that the water we drink is cleaner. Clean water does not cause diseases（疾病）. Besides, medical treatment is better today. More and more people live to be over eighty.

    Women often live longer than men. For example, in Japan, women usually can live to be eighty-five, but men can only live to be eighty.

    In the future, people will probably live longer than today. Here are many things we can do to help people live longer. For example, we can make sure that everyone has enough medicine to fight against diseases. Also, it is necessary for everyone to have enough to eat. Today many people die because they do not have enough food.

    The world has a plastics problem. And not just with bottles. Straws (吸管), toothbrushes, toys—all kinds of plastics are placed in landfills. There are 5 billion tons of plastic waste in the world. Landfills have a large part of it. By 2050, they could have 13 billion tons.

    Much of plastic rubbish finds its way into the ocean. Scientists say 165 million tons of plastic pieces are floating around out there. And most plastic won't disappear itself. It will remain in the ocean forever. Whales get caught in plastic fishing nets. Birds die because of eating plastic straws and bottle caps. It endangers ocean life. Plastic rubbish even ends up in the food we eat.

    Governments are realizing that recycling may not be enough. They are taking more actions. Though it is hard work, it is still a solvable problem. In Britain, people are not allowed to use plastic bags except in hospitals. Scotland and several coastal cities in the US stop people from using plastic straws as well. The US alone throws away some 500 million plastic straws a day. That's enough to circle the Earth twice. "Saying no to a plastic straw is an easy way to make a big difference," Diana Lofflin who started www.strawfree.org said. "'Do we really want to pass on to our children a world harmed by plastic?"

    People have found some tasty ways to reduce waste. A company in India made the first-ever spoon that people can eat. You don't have to eat the spoon. You can throw it away. It decomposes (分解) in just a few days. David Edwards, a scientist at Harvard University, designed an eatable bag which can protect the food or drink inside. It is a delicious replacement for plastic ones.

    The world got a glimpse(一瞥) of one of the greatest mysteries of our universe(宇宙) on April 10.

    That′s when the first image of a black hole was shown to the public. The picture was created by a network of eight radio telescopes(射电望远镜).

    "We have seen what we thought was unseeable, "says Shep Doeleman. He led the effort to create the image.

    The black hole is at the center of galaxy (星系)named Messier 87, some 55 million light﹣years from the earth, and is 6.5 billion times the mass of the sun.

    The image shows the gas, dust, and stars that move around the black hole before disappearing into it. It does not truly show the black hole, because not even light can escape its gravity. Black holes, like vacuums, suck(吸)in everything that gets too close.