Ladies and gentlemen, I returned to this year in a time machine. In the year 2500, we are able to travel through time to any year in the history of the earth. This year is your last chance your lifestyle to save the earth.

    Beginning in the middle of the 20th century, a few people were worried about polluting the earth's water and air, but most people did not change their way of life. Instead, they continued to pour(倒) dangerous chemical(化学物品) and other waste into lakes and seas, to drive more and more cars and trucks, and to cut down trees.

By the year 2200, the earth's water was completely polluted. People could no longer drink water, and they had to use other types of liquids(液体). Scientists said that in the future there might be too many people on the earth. But not enough was done.

So by the year 2300, there were so many people that food became scarce. There was no water to grow food and all of the fish in lakes and seas died because of pollution. Terrible wars broke out between the rich and the poor. Scientists were working very hard to find another planet in space where humans could live.

By the year 2400, the air was too polluted for humans to breathe. So we had to leave the earth. But only the rich were able to leave. Where did we go? Nowhere. And everywhere. You see scientists did not find another safe planet, so now we must travel around the universe in our space ships. We are still looking for a place to call our home.

    So it is up to you to change history. There is still hope. You must change your lifestyle now, before it is too late.

    Lockheed Martin, American space system company (空间系统公司) has found a really cool way to inspire the young minds of today to the research fields in Science, Technology, Engineering and Math (STEM).

    It may look like a normal yellow bus, but all the magic happens once you get inside. Meet the “Mars (火星) Experience Bus,” part of Lockheed Martin's new “Generation Beyond” national education program to get the kids joining in studying what goes on outside of our home planet. The bus offers a virtual reality (VR, 虚拟现实) experience making the teenagers feel like they are driving on Mars.

    The VR experience was developed by taking advantage of software (软件) created for today's best video games, so you can imagine the picture shown is top level. The kids do seem really excited to see the bus take a virtual trip on the red planet and search unknown places. It's certainly a great way of learning about the universe by virtual reality working on a common bus.

    The Lockheed Martin's bus will start a tour in the United States to allow kids from different parts of the country to take a ride in it. The Generation Beyond project also includes an iPhone app for iOS providing real-time information about weather reports for Mars, and there's also a free deep space course for middle school teachers and students.

    Many scientists find that colors can change people's feelings. It's very interesting. Some colors can make people feel relaxed, and some colors can make people feel nervous. Now, this kind of knowledge is being used in many places. For example, school walls are always painted green because green makes students feel relaxed. It is also good for the students' eyes. Some books are also green or light blue for the same reason. Restaurant owners not only have to know how to make food, but also have to know how to make money. Here are some things they've learned from scientific studies. The color red makes people hungry. Many fast food restaurants have red furniture or walls. Soft colors like pink and light blue make people feel relaxed, so they spend more time eating. Loud music may be nice at first, but it soon makes people want to leave. Hard seats also make customers want to eat quickly and leave. Many restaurants, especially fast food restaurants, use this knowledge to make customers eat faster.

    What's a spacewalk? Any time an astronaut gets out of a spacecraft(航天器) while in space, it is called a spacewalk. Astronauts go on spacewalks for many reasons. For example, experiments can be placed on the outside of a spacecraft. This lets scientists learn how being in space affects(影响) different things. By going on spacewalks, astronauts can also fix things instead of bringing them back to the earth to fix.

    When astronauts go on spacewalks, they wear spacesuits to keep themselves safe. Inside spacesuits, astronauts have the oxygen(氧气) they need to breathe and the water they need to drink. To keep the astronauts and the spacecraft safe, the astronauts must leave and go back to the spacecraft through a special door. When on a spacewalk, astronauts use safety  tethers to stay close to their spacecraft. Tethers are like ropes, connect the spacewalkers with the spacecraft. They keep astronauts from floating(漂浮) away into space. Another way astronauts stay safe during spacewalks is by wearing a SAFER. SAFER is worn like a backpack. It helps an astronaut move around in space.

    How do astronauts train for spacewalks? One way is by going for a swim. Floating in space is a lot like floating in water. Astronauts practice spacewalks underwater in a huge special swimming pool. For every one hour they will spend on a spacewalk, astronauts need to train seven hours in the pool. Another way astronauts practice for a spacewalk is by using virtual reality(虚拟现实). It looks and feels just like a spacewalk.

    Today, only three countries have finished spacewalks independently. They are Russia, the United States and China. The first person to go on a spacewalk in the world was Alexei Leonov from Russia. Zhai Zhigang is the first Chinese astronaut to go on a spacewalk. The world record of spacewalks is held by Russian astronaut Anatoly Solovyev. He has been on 16 spacewalks and spent more than 82 hours outside in space.

Why is music important to people? Because life{#blank#}1{#/blank#}music wouldn't be active. Different kinds of music express different life experiences. So, when we listen to different kinds of music, they can bring us different {#blank#}2{#/blank#}. For example, rock music can make us {#blank#}3{#/blank#}, classical music can make us relaxed; and country music can make us think of the beautiful country life. At different ages, people have different ideas about music. Young people today enjoy pop music {#blank#}4{#/blank#}their parents prefer listening to classical music. Perhaps this is. because young people are {#blank#}5{#/blank#}with energy and faster music can let their energy come out. Their parents have worked very hard during the day and they have got tired when they come back home. So, they would like to listen to classical music to make themselves relaxed. 

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Doing Housework

Last week, our class made a survey on doing housework among ourselves.