B

    Surtsey was born in 1963.Scientists saw the birth of this island. It began at 7.30 a.m. on 14th November. A fishing boat was near Iceland. The boat moved under the captain's（船长）feet. He noticed a strange smell. He saw some black smoke. A volcano（火山）was breaking out. Red-hot rocks, fire and smoke were rushing up from the bottom（底部）of the sea. The island grew quickly. It was 10 meters high the next day and 60 meters high on 18th November. Scientists flew there to watch. It was exciting. Smoke and fire were still rushing up. Pieces of red-hot rock were flying into the air and falling into the sea. The sea was boiling and there was a strange light in the sky. Surtsey grew and grew. Then it stopped in June 1967.It was 175 meters high and 2 kilometers long. And life was already coming to Surtsey. Plants grew. Birds came. Some scientists built a house. They want to learn about this young island. A new island is like a new world.

    A recently study found people's lives are made shorter in North China. It is showed the life expectancy(平均寿命) had been cut down by 5.5 years there. Researchers think that the heavy air pollution in China should be to blame. It's really the truth. Our government has already done something. However, it doesn't seem to work so well.

    “Air pollution in China is doing harm to people's health. The harm is much more serious than we can imagine,” said Chen Yuyu of Beijing University, one of researchers of this study.

    Dirty air brings serious problems in North China. In January this year, the air pollution was worse than that in other places. That was caused by rising temperature and waste gas from coal heating.

    Chinese government should strongly fight against air pollution. They should think of more proper ways to deal with the problem. People should be encouraged to take buses, ride bicycles or walk, instead of driving cars. The factories that pollute heavily should be closed.

    “We need to improve our environment, although it might be expensive. Protecting our environment means protecting ourselves,” Li Hongbin, another researcher of the study said.

    Technology is everywhere. We see it any place we go and, in fact, almost all of us carry some piece of technology with us every time we leave the house. What I always forget, though, is just how useful and powerful technology can be when we want to help others.

    There is not a single room in my house that does not have some electronic devices （设备）lying around in it. Whenever I am at home, I am almost always using at least one electronic device. If you walked into my living room on any given day, you would find that, first, I have the television on. At the same time, I usually have my laptop resting on my knee, or I will be using my mobile phone. Even when I'm not at home I am always using my phone, and at work or in cafés, I sit down and connect to the local wireless network on my laptop.

    I must say that I waste a lot of time on the computer and the time I spend on it could be much better spent if I were to take up a little online volunteering.

    The technology we carry about everywhere can have a great power to do good for the world and to help others and recently I discovered just how much online volunteering there is to do in the world. From using your language skills to do translations, to developing and managing projects and helping with IT work, there is so much that so many people can do to help people in their own countries and across the world. The United Nations, in fact, has a huge page with "Volunteers Recruited" on its website.

    This work can support the poor and help charities who cannot pay for staff members. Many organizations only require you to work an hour a week﹣some even less. And the support provided by online volunteers can really help make a difference to those in need.

Would it surprise you to learn that, like animals, trees can communicate with each other and pass on their wealth to the next generation—their young trees?

    Suzanne Simard, forest ecologist(生态学家) at the University of British Columbia, explains how trees are much more complex(复杂的) than most of us ever imagined. Although Charles Darwin(达尔文) thought that trees are competing for survival of the fittest, Simard and her team have made a new discovery and showed just how wrong he was. In fact, the opposite is true: trees survive through their group work and support, passing around necessary nutrition(营养) such as nitrogen(氮) and carbon "depending on who needs it".

    Nitrogen(氮) and carbon are shared through miles of underground fungi (真菌) networks. This makes sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This system works in a very similar way to the networks of neurons (神经元) in our brains, and when one tree is destroyed, it influences all.

    Simard talks about "Mother trees". These are usually the largest, oldest plants that on which all other trees depend. These "Mother trees" are connected to all the other trees in the forest by this network of fungi, and may manage the resources of the whole trees and plants in the forest. She explains how these trees pass on the wealth to the next generation, transporting important resources to young trees so they may continue to grow. When humans cut down "Mother trees" without paying attention to these highly complex "tree societies" of the networks on which they feed, we are reducing the chances to save the whole forest.

    "We didn't take any notice of it," Simard says sadly. "Mother trees" move nutrition into the young trees before dying, but we never give them chance. If we could put across the message to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.

Why does the sky change colors?

    What is the sky? How high is it? What color is it? What birds can live above it? These questions are difficult to answer, aren't they?

    In fact, the sky has no color. Then why does the sky look blue?

    We know that there is air around the world. When planes fly, they need air to lift their wings. Planes can't fly very high. That is because the air gets thinner when they go higher. The same will happen to us if we go high enough. If we go up about 1, 200 kilometers from the earth, we'll find no air there. Some birds can fly into the sky as high as a plane, but they cannot fly or live without air.

    Looking up above us, you will see the blue sky with white clouds. It is usually light blue. The color would be bluer when you see on the top of a high mountain. And you will see fewer clouds in the sky between you and the sun.

    Sometimes the sky doesn't look blue. When the sun rises and falls, you will see red, orange, and other colors in the sky. Such are the most beautiful moments of the day.

    Who can see the colors of the sky high above the earth? The astronauts! They can see those beautiful colors of the sky from the outer space. However, before flying into outer space, they sit in a spaceship high above the earth, and there is no air at all. The sky would be that dark and its color would be black.

    Now you may understand that we see colors because the air scatters(使散射) the sunlight. light travels through the air. Without air, there would be no light or colors.