“ Can we go now, Momma?” little Susie asked, pulling on her mom's arm. Her mother did not answer, only stared blankly at the scene below. Crowds of people marched about with what looked like picket(警戒队) signs. Other people gathered around them, shouting angry words that she couldn't make out from this distance. This relatively small town in Missouri had never seen so much action. She and Susie were standing at the top of the only high rise building in town for Susie loved to try to find their house among the rows and rows of little boxes.

    “Momma? ” Susie said in a frightened voice, two seconds before a gun shot went off, making her scream at the top of her lungs. Her mom grabbed her and held her over her shoulder as the tears started pouring. “What was that? I'm scared, Momma!!”

    “Sh Sh Sh,” her momma whispered in a soothing tone, rubbing her daughter's hair. “It's just a bad dream, baby. She said both to herself and Susie.

    Susie looked at her with confused eyes at the same time a fight broke out among some members of each group. The little girl gasped in surprise. “Why are those ants fighting , Momma?”

    “Those aren't ants, sweetie; they're people, or, at least they're supposed to be.”

    “I don't understand what's going on! I'm scared!!” the four-year-old child clung to her momma. “It looks like they're dancing, momma.”

    “Yeah, it sort of does, doesn't it?” her mother said with an air of disbelief. How could the expression of heated anger be so beautiful? It was so wondrously unexpected that it brought soft tears to her eyes.

    “Why are you scared, Momma? It's just bugs dancing,” Susie said with an innocent smile, wiping away her mother's tears.

    Far from the land of Antarctica (南极洲), a huge shelf of ice meets the ocean. At the underside of the shelf there lives a small fish, the Antarctic cod.

    For forty years scientists have been curious about that fish. How does it live where most fish would freeze to death? It must have some secret. The Antarctic is not a comfortable place to work and research has been slow. Now it seems we have an answer.

    Research was begun by cutting holes in the ice and catching the fish. Scientists studied the fish's blood and measured its freezing point.

The fish were taken from seawater that had a temperature of -1.88℃ and many tiny pieces of ice floating in it. The blood of the fish did not begin to freeze until its temperature was lowered to

-2.05℃. That small difference is enough for the fish to live at the freezing temperature of the ice-salt mixture.

    The scientists' next research job was clear: Find out what in the fish's blood kept it from freezing. Their search led to some really strange thing made up of a protein (蛋白质) never before seen in the blood of a fish. When it was removed, the blood froze at seawater temperature. When it was put back, the blood again had its antifreeze quality and a lowered freezing point.

    Study showed that it is an unusual kind of protein. It has many small sugar molecules（分子）held in special positions within each big protein molecule. Because of its sugar content, it is called a glycoprotein. So it has come to be called the antifreeze fish glycoprotein, or AFGP.

    If doctors want to test you for something, they'll usually take a blood or urine sample. But wouldn't it be much more convenient if they just asked you to breathe through a special instrument?

    In fact, your breath can say a lot about you. In traditional Chinese medicine, doctors draw a conclusion about the health state of a patient based on the smell of his or her breath; trained dogs and rats can identify the smells of the breaths of people suffering from certain cancers; traffic police also monitor drivers' alcohol consumption by testing their breaths.

    Just like blood and urine, your breath contains lots of “metabolites” —the waste chemicals that the body produces, which vary from person to person. They are like personal health fingerprints, which is why scientists sometimes call them “breathprints”, according to Science Daily.

    Compared to blood or urine testing, breath testing takes only seconds instead of hours, and it requires neither a needle nor a container to hold the body fluids(液). This means the test can be taken frequently to better detect early signs of diseases and monitor the progress of a medical treatment.

    On the other hand, as an identifier, you might think that breaths are not as reliable as fingerprints since they might change based on what you eat. However, researchers in Zurich, Switzerland mapped 11 healthy volunteers' chemical patterns by having them breathe through a special instrument, and they found that each pattern was unique and the patterns didn't change much throughout the day, reported BBC.

    “Our goal is to develop breath analysis to the point where it becomes competitive with the established analysis of blood and urine,” said Malcolm Kohler, professor at the University Hospital Zurich.

    As a gesture of friendship，Mayor Yukio Ozaki of Tokyo，Japan gave Washington, D.C a gift of more than 3,000 Japanese cherry trees on March 17,1912.Every spring, the cherry trees in Washington，D.C. take bloom(开花)，beginning one of the country's loveliest celebrations, the National Cherry Blossom Festival (March 17-April 15). Book your trip now to see this vibrant display of pink and white in this city full of history!

    Washington, D.C. Cherry Blossom In-Depth Tour

    Priee: $45/person

    Available: Mar.25-Apr.15

    Duration: 1 Day

    Highlights: Visit Washington， D.C.; experience the peak period of cherry blossom(April 8-12)

    Itinerary: Guests will start to celebrate the National Cherry Blossom Festival and discover the beauty of cherry blossoms. Next,we will begin our sightseeing city tour including Lincoln Memorial, White House, US Capitol, Madame Tussauds Wax Museum, Washington Monument and International Spy Museum. Then visit the next tourist spot, the Jefferson Memorial. It's the best location to view the cherry blossoms. Finally, guests may board a Potomac River cruise to see the city from the water. Then tour ends.

    Price Includes: Ground Transportation

    Admission Fees:

    Note: If you would like to join in the optional activities, please pay the fee in cash to the tour guide. You cannot buy the tickets on your own or use City Pass. The tour guide will arrange the tickets for the group.

    Moving flight times from night to day could reduce air travel's contributions to global warming, a new study suggests. Scheduling more (lay time flights may reduce the influence of contrails ——the visible lines of white steam that many planes leave behind them in the sky.

    The role of contrails in climate change is still being studied, but some scientists believe they contribute to the greenhouse effect by trapping heat in the atmosphere.

    Nicola Stuber, first author of the study, suggests that contrails' overall impact on climate change is almost as big as that of aircraft^? s carbon dioxide emissions (排放)over a hundred-year period. Aircraft are believed to be responsible for 2-3% of human carbon dioxide emissions. Like other high, thin clouds, contrails reflect sunlight back into space and cool the planet. However, they also trap energy in the atmosphere and increase the warming effect.

    Stuber and other scientists believe that the effect of the contrails is big. "On average, the green-house effect controls the effects of contrails, said Stuber, a meteorologist at England's University of Reading." The warming effect is far greater for contrails left by night flights," Stuber added. "The cooling effect only happens (luring the day when the sun is up. During the night the greenhouse warming is no longer balanced and that is why the contribution of night-flight is so large."

    Most commercial airline traffic occurs during daylight hours. For example, only one in four United Kingdom flights is a night flight, but those flights create some 60% of the warming created by contrails, the study reports.

    If you're DIY-minded, you can build your own solar power system. In some cases, you can even build your own solar panels (电池板), although the amount that you can effectively DIY home solar depends on how much you want to power. Making your own solar panel is a time-consuming process and requires some electrical skills. However, it can also be very rewarding-learning to build your own panel is a great way to understand how solarelectricity is generated.

    Before you can build your own solar panels, you first need to understand how solar cells generate electricity. Once you've bought individual solar cells (they can be purchased online), the basic process for building your own solar panel goes like this: Prepare the backing for your panel. Many DIY solar panel builders prefer to use a wooden board as the base for their solar cell. You'll need to drill holes in the board so that the wires for each cell can pass through. Wire your solar cells together. This requires some experience with electrical work. Use a soldering iron (烙铁) to attach wire to the solar cells and then link each of the cells together. Attach cells to your backing. If possible, attach each solar cell to the backing individually. This makes it easier to replace a single cell in the event that becomes damaged or is not operating properly.

    At this point you have a functional solar panel that can produce electricity when the sun shines. However, a solar panel by itself is not useful. If you are trying to generate electricity to power devices in your home, you need to pair your panel with an inverter (换流器) that will turn direct current (DC) power from the sun into the alternating current (AC) power used in most modern electronic devices.