Ask someone what they have done to help the environment recently and they will almost mention recycling. Recycling in the homes is very important. However, having to recycle often means we already have more products than we need. We are just dealing with the results of that over-consumption in the greenest way, but it would be much better if we did not bring so many goods home.

    The total amount of packaging（外包装）has increased by 12% between 1999 and 2005. It is 1/3 of a home's waste in theUK. In many supermarkets, food products are packaged twice with plastic and paper. Too much packaging is doing serious damage to the environment. The UK, for example, is running out of land because of this unnecessary waste. If such packaging is burnt, it gives off greenhouse gases which go on to cause the greenhouse effect. Besides, the plastic from the package puts some creatures indanger, especially birds and fish.

    Recycling helps, but the recyclingitself uses energy. The solution is not to produce such waste in the firstplace. Food waste is a serious problem, too. Too many supermarkets encourage customers to buy more than they need. However, few of them have the idea that this cannot continue. For example, supermarkets should encourage customers to reuse their plastic bags.

    But this is not just about supermarkets. It is about all of us. We have been used to the idea that packaging means excellence while anything unpackaged is of poor condition. This is especially true of food. But this idea has spread to other products, which often have farmore packaging than necessary.

    There are signs of hope. As more of us recycle, we are beginning to realize just how many unnecessary goods are collected. We need to face the waste of our consumer culture, but we have amountain to climb.

    Scientists have always believed that snails are not able to find their way home. But Briton Ruth Brooks, a retired teacher, has found that it is not true.

    Brooks began an experiment on snails after she got mad with the snails in her garden.

    The snails had eaten her vegetables. She didn't want to kill them, so she took them to another place. But she found they always seemed to come back.

    Brooks did an experiment. She marked the snails in her garden with nail polish(指甲油).

    She placed the snails in the area around her home and made notes of their movements.

    She found that snails have a strong homing instinct (本能); the longest returning snail traveled back 90 meters. Brooks has been named Britain's best amateur (业余的) scientist after her work won the BBC Radio 4 project, So You Want To Be A Scientist.

    She said, "I've always wanted to know whether the snails that eat my plants just come back when I move them, and if they do, what is their homing distance?

    "I would say on the evidence (证据) that it would be safe to take your snails away beyond 100m or even further. If you put them somewhere nice with some food, you can be almost certain that they won't come back."

    Artificial intelligence (AI) (人工智能）is the ability of a computer program or a machine to think and learn. It is also a field of study that tries to make computers "smart". John McCarthy, a scientist, came up with the name "artificial intelligence" in 1955. Many things such as learning and problem solving can be done by computers, though not in the same way as we do.

    An unusual goal of AI research is to create computer programs that can learn, solve problems, and think logically(逻辑地）. At present we use the term Al for successfully understanding human speech, recognizing(识别）human faces, operating self-driving cars and competing in some game systems like Chess and AlphGo（阿尔法狗）. Some people also consider AI a danger to humans if it develops too quickly. Professor Stephen Hawking (霍金), a well-known British scientist, was not for this kind of technology.

    Math is the basic language of AI. If we raise the standard in the learning of math, our students will be more likely to become successful AI designers in the future. We not only want bright students, but also need to attract average students and give them the math skills which are needed to change them into AI designers. Besides, a good knowledge of computer science is also necessary for AI designing.

    Scientists hope to create creative and emotional AI which can possibly understand human feelings or create art. Many ways and tools have been tried to discover this fascinating field.

    My mother used to ask me what the most important part of the body was. I got different answers at different ages.

    When I was young, I thought sound was very important to us, so I said, "My ears, Mum. "But she shook her head and said no. Several years passed, and she asked me again. I believed that I got the right answer after thinking it over. So I told her，"Sight is very important to everyone, so it must be our eyes. "But she told me I was wrong. I tried many times after that, but her answer was always the same. Till last year, my grandma died. Everybody was crying, and everybody was hurt. My mom looked at me and asked me with tears in her eyes，"Do you know the answer now？"I was surprised when she asked me this question then. "My son, the answer is your shoulder. Everyone needs a shoulder to cry on. "

    Finally, I realized (意识到)all she hoped is that I can have enough love and friends so that I will have a shoulder to cry on when I need it.

    How green are you? Do you know how to be green?

    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.

    Reduce

    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 whether it is really necessary-or maybe the old one will be just as good! When we buy things, choose local products if possible, and try not to buy too many things from abroad.

    Reuse

    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 look after 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(瓷器) cup and a lunch box because you can use them again.

    Recycle

    Recycle means "change things into something else". Though 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 neighborhood and take part in recycling programs. We should also buy products made from recycled materials, such as recycled paper, to help save trees.

    So please remember these three words: reduce, reuse and recycle.

    Many people know that rubbish is a big problem on planet Earth. What many people don't know is that junk has become a problem in outer space too.

    According to BBC News, there are more than 22,000 pieces of space junk floating around the earth. And these are just the things that we can see from the surface of the earth by telescopes (望远镜). There are also millions of smaller pieces of junk that we can't see.

    Objects, like bits of old space rockets or satellites, move around the planet at very high speeds, so fast that even a very small piece can break important satellites or become dangerous to astronauts. If the smallest piece of junk crashed into a spaceship, it could damage it.

    To make things worse, when two objects in space crash, they break into many smaller pieces. For example, when a U.S. satellite hit an old Russian rocket in 2009, it broke into more than 2,000 pieces, increasing the amount of space junk.

    To reduce additional space junk, countries have agreed that all new space tools can only stay in space for 25 years at most. Each tool must be built to fall safely into the earth's atmosphere after that time. In the upper parts of the atmosphere, it will burn up.

    Many scientists are also suggesting different ways to clean up space junk. In England scientists are testing a metal net that can be fired into space junk. The net catches the junk and then pulls it into the earth's atmosphere to burn up. The Germans are building robots that can collect pieces of space junk and bring them back to Earth to be safely destroyed.

    "The problem is becoming more challenging because we're sending more objects into space to help people use their mobile phones and computers," says Marco Castronuovo, an Italian space researcher.

    "The time to act is now. The longer we leave the problem, the bigger it will become," he says.