There are many colors in nature. But do you think that a color has weight? I think you'll say 6/no". But I'm afraid you are wrong. If you don't believe it, you may do a small experiment(实验).

  First, put two objects with the same weight into two boxes. Then cover the boxes.Third, wrap(包裹) one box with a red piece of paper, the other one with a white piece of paper. OK. Now hold the boxes with your hand one by one. It is certain that you will think the red one is a little heavier.

 Why do you think so? A scientist found that different colors have different weights in man's mind. That is to say, every color has its own weight in our mind.

 The scientist told us that colors also have smell. Can you smell the color? Of course not. Then why did the scientist say S07 That is because every color stands for (代表) a kind of light with a certain wavelength,(波长). It reaches our brain through sense organs

 According to this discovery, scientists say that people accept the colors they like, and refuse the colors they hate. So your body and mind will be healthy by using the colors you like. Or you'll be nervous or even get ill.  For example (例如) ,  you like blue and hate red.  If you stay in a room with red windows, wallpaper and furniture（家具) for two hours, you'll feel you have been there for four hours. But if the room is blue, you'll feel you have been there for only an hour.  And, if a person walks out of a blue room and into a red room, his temperature will rise.That means our body temperature will change with different colors.

    All over the world the need for more laptops and computers increases each year. Networks have been part of our life. Probably everyone with a portable device （移动设备）has once logged on to a public WiFi network without paying for it, while they are having a coffee, on a train, in a shopping mall or at a hotel. However, is this kind of public WiFi network safe?

    Some networks are better protected than others because encryption （加密）methods are used. Therefore, they are safer than others. But a survey in 2015 showed that more than 950 million records were not protected, including addresses, emails, birth dates, phone numbers, passwords and so on. These open WiFi networks are really not safe, because it is very easy for hackers （黑客） to break into the operating system and get people's private information.

    Most smartphones and laptops, by themselves, search and connect to WiFi networks. They usually prefer a network with a connection that has been used before. Hackers' devices are able to record these searches and look like the trusted WiFi networks. When these smartphones and laptops log on to the networks which are not real, hackers can easily steal their private information.

    So next time, when we want to use our laptops or our smartphones in public places which offer free WiFi networks, please think it twice or take safe measures before using them.

    My house is made of wood, glass and stone. It is also made of software.

    If you come to visit, you'll probably be surprised when you come in. Someone will give you an electronic PIN to wear. This PIN tells the house who and where you are. The house uses this information to give you what you need. When it's dark outside, the PIN turns on the lights nearest you, and then turns them off as you walk away from them. Music moves with you too. If the house knows your favorite music, it plays it. The music seems to be everywhere, but in fact other people in the house hear different music or no music. If you get a telephone call, only the nearest telephone rings.

    Of course, you are also able to tell the house if you want something. There is a home control console (控制台), a small machine that turns things on and off around you.

    The PIN and the console are new ideas, but they are in fact like many things we have today. If you want to go to a movie, you need a ticket. If I give you my car keys, you can use my car. The car works for you because you have the keys. My house works for you because you wear the PIN or hold the console.

    I believe that several years from now on, most new homes will have the systems that I've put in my house. The systems will probably be even bigger and better than the ones I've put in today.

    I like to try new ideas. I know that some of my ideas will work better than others. But I hope that one day I will stop thinking of these systems as new, and ask myself instead, “How did I live without them?”

    Do you know why different animals or pests (昆虫) have their special colors? Colors in them seem to be used mainly to protect themselves.

    Some birds like eating locusts (蝗虫), but birds cannot easily catch them. Why? It is because locusts change their colors together with the change of the colors of crops(庄稼). When crops are green, locusts look green. But as the harvest time comes, locusts change to the same brown color as crops have. Some other pests with different colors from plants are easily found and eaten by others. So they have to hide themselves for lives and appear only at night.

    If you study the animal life, you'll find the main use of coloring is to protect themselves. Bears, lions and other animals move quietly through forests. They cannot be easily seen by hunters (猎人). This is because they have the colors much like the trees.

    Have you ever noticed an even stranger act? A kind of fish in the sea can send out a kind of very black liquid (液体)when it faces danger. While the liquid spreads over (散开), its enemies (敌人)cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.

    Why do we like drinking water from plastic bottles? Some people think it is healthy and clean. Others drink bottled water because it's easy--you can carry it around with you. In hot countries, like Greece, we often buy bottles of cold water in the summer.

    However, making tots of plastic is not a good idea for many reasons. First of all, we need a lot of oil for plastic products. We usually use oil as a source(资源) of energy. If we reduced the number of bottles we made, we wouldn't need so much oil. Plastic bottles also pollute the environment. If we recycled all our plastic bottles, we wouldn't need so much space for rubbish dumps. But in Greece, we don't recycle much of the plastic we use. In 2006, Greeks recycled only about 10% of plastic waste. The rest became rubbish on land and in rivers and seas.

    So next time you want to throw away a plastic bottle in the litter bin, stop and think. If you recycled it, you would help the environment. But what can you do when there isn't a recycling bin near you? Well, there are lots of useful ways that you can use your bottles again. For example, an empty bottle makes a great piggy bank for your pocket money, and if you cut a bottle in half, you will have a plant pot. Go green! You can make a difference.