C

    This year's winner of the Nobel Prize in Medicine is from Japan. According to his research, cells (细胞) sometimes "eat" themselves to keep healthy. In other words, cells can break down old ones and use the useful parts to make new cells, or to fight off viruses (病毒). This new finding could help scientists fight many diseases.

Small machines

    Three scientists from France, the United Kingdom and the Netherlands (荷兰) won the Nobel Prize in Chemistry for their work on small machines. How small? Well, they are a thousand times thinner than a strand (缕) of hair. We can't see them with only our eyes! This technology will open a whole new world for us. For example, we could make very small robots in the future. A doctor could put them into our body. Like policemen, the robots look for the ill parts in our body, and send the medicine right there.

Super-state

As teachers said in your physics class, most things in the world are in three states: solids (固体), liquids (液体) and gases . But at very low or high temperatures, things can turn into a strange state. For example, break down things to their smallest pieces and we get "atoms" (原子). Like Lego building blocks, atoms usually add up to become a 3-D thing, like a box. But atoms in the strange state don't. They stay together and become a flat thing, like a piece of paper.

    This is a new finding of three British-born scientists. And they won the Nobel Prize in Physics this year. They hope to use things in this strange state to make new materials.

About the Prize

    The Nobel Prize was started by Swedish inventor, Alfred Nobel in 1895. It gives prizes to great science research and the people behind it. Every year in October, the Royal Swedish Academy of Sciences decides who wins. It includes six prizes: chemistry, physics, physiology (生理学) or medicine, peace, literature (文学) and economic. This year each winner gets a medal and prize money of more than 6 million yuan.

根据短文内容，选择最佳选项。

    Everybody needs water. Everything needs water. We use water to wash the bowls(碗), clothes and ourselves. We use water to plant trees, flowers and crops(庄稼). Where does all water come from? It comes from clouds.

    Some of rain goes into the ground. Many people get it under the ground. Some rain water goes into the hills. It runs into lakes and rivers. Many people get it there.

    Some of the greatest problems we face today are the destruction (破坏) of our environment. Brown clouds, polluted water, endangered wild animals.., these problems seem so huge.

    So my family does what we can. We take cloth bags to stores instead of using plastic bags. We walk where we don't have to drive...

    But does it do any good? When I am the only one in line at the market with cloth bags, am I doing any good? Does my walking to stores make any real difference to the world?

    I recently learned something about flamingos (火烈鸟) which like to get together in groups of a thousand or more. Every year, when the time comes for migration (迁徙), a few of them first takeoff from the lake. But none of the others seem to notice, so the small group returns. However, the next day they try again. This time few more fly along with them, but most of them still pay no attention, so they return again. They try for several times. Every time a few more birds join in but, since the thousands of others still take no notice, the great migration plan is once more stopped.

    Then one day something changes. The same small group of birds once again starts flying and a small number more join in just as before, then more. Finally, they all take flight and the migration really begins. What a spectacular sight it must be—thousands of flamingos taking off into the sky at once!

    A few can make a difference. Even if you're the one to take the first step, and continue trying, others will someday take notice and together we will solve even our greatest problems.

    Like most people, your intelligence（智力）changes from season to season. You are probably a lot sharper in spring than you are at any time of the year. A well known scientist, Ellsworth Huntington concluded（得出结论）from other men's work and his own that climate and temperature have a clear effect on people's intelligence.

    He found that cool weather is much better for creative thinking than warm weather, but this doesn't mean that all people are not so quick at learning in summer as they are during the rest of the year. It doesn't mean, however, that the intelligence of a large number of people seems to the lowest in summer.

    Spring season appears to be the best period of the year for thinking. One reason may be that in spring man's intelligence is affected（影响）by the same factors（因素）that bring about great changes in all nature.

    Autumn is the next-best season, then follows winter. As for summer, it seems to be a good time to take long holidays from thinking.

    Do you know when Earth Day is? It is on April 22nd, and it began in the US in 1970. Earth Day in our country began in the 1990s. Earth Day is a good time for people to think about what they can do to make the Earth clean and beautiful, because now the environment on Earth is getting worse and worse. In fact, there are many things we can do to protect our Earth.

    Plant trees.

    Planting more trees helps to reduce greenhouse gases (温室气体), stop the earth from running away and provide homes for animals.

    Don't waste.

    Do not waste water. Use both sides of paper when you write. Turn off the light when you leave. Take your cup with you. Take your own shopping bags to the supermarket. Stop using the plastic bags. Don't use any disposable things. We should save energy.

    Don't throw rubbish in the streets.

    When rainwater washes over the rubbish, it becomes polluted. The polluted water flows into the rivers and seas.

    Ride your bike or take a bus.

    Too many cars pollute the air and waste energy.

    Remember: Every day is Earth Day.

    We should protect the Earth every day, not just on Earth Day. The Earth is our home. Let's do our best to make the Earth cleaner and more beautiful.

Everybody dreams. But only some people remember their dreams. Our dreams often include all the senses —- smells, sounds, sights, tastes and things we touch .Sometimes we dream the same dream over and over again.

    Early in the twentieth century, two famous scientists developed their personal ideas about dreams. Austrian psychiatrist (奥地利心理学家) Sigmund Freud wrote a book called "The Interpretation (诠释) of Dreams" in 1900. Freud believed people often dream about things they want but can't have. Swiss (瑞士) psychiatrist Carl Jung worked closely with Freud for several years, but he believed dreams provide solutions to problems we face when we are awake.

    Other researchers are studying how dreaming helps our bodies work with problems and very sad emotions (感情). Robert Stickgold is a professor of psychiatry (心理学教授) at Harvard University in Massachusetts. He says that when we dream, the brain is trying to make sense of the world. He does not agree with Sigmund Freud that dreaming is the way we express our hidden feelings and wishes.

    Scientists believe it is important to keep researching dreams. Doctor Stickgold says it's more than one hundred years since Sigmund Freud wrote his important book about dreaming. Yet there is still no agreement on exactly how the brain works when we are dreaming or why we dream.