In colonies (群体) that range in size from a few hundred to tens of millions, they organize their lives with a clear division of labor. Even more amazing is how they achievethis level of organization. Where we use sound and sight to communicate, ants dependprimarily on pheromone (外激素), chemicals sent out by individuals and smelled or tastedby fellow members of their colony. When an ant finds food, it produces a pheromone that will lead others straight to where the food is. When an individual ant comes under attack or is dying, it sends out an alarm pheromone to warn the colony to prepare for a conflict as a defense unit.

         In fact, when it comes to the art of war, ants have no equal. They are completely fearless and will readily take on a creature much larger than themselves, attacking in large groups and overcoming their target. Such is their devotion to the common good of the colony that not only soldier ants but also worker ants will sacrifice their lives to help defeat an enemy.

         Behaving in this selfless and devoted manner, these little creatures have survived on Earth, for more than 140 million years, far longer than dinosaurs. Because they think as one, they have a collective (集体的) intelligence greater than you would expect from itsindividual parts.

    In today's busy and competitive world, we all lead incredibly stressful lives. When stress becomes overwhelming, it can affect our mood and productivity.{#blank#}1{#/blank#} The good news is that it is manageable and can be reduced, or even relieved completely.

    Enter the world of books. Feeling stressed out? Pick up your favorite book and leave the reality and worries behind. It is the most effective way to relax and overcome stress.{#blank#}2{#/blank#} Getting lost in a book before bedtime can calm your mind and prepare your body for a good night's sleep.

    Connect with people. Another way to successfully beat stress is meeting with friends. Friends and loved ones are important to any healthy lifestyle. If you're feeling a little overwhelmed and just can't seem to shake it off, call your best friend or a member of your family and talk to them.{#blank#}3{#/blank#}

    Walk it off. You can also effectively relieve yourself of stress by simply taking a walk around your neighborhood.{#blank#}4{#/blank#} There's a whole new world up there that you never seem to notice while rushing to work or talking to someone. Take a moment to admire a new building or a balcony somewhere high up that reminds you of a castle from your favorite movie. Enjoy your time alone and seize every moment of it.

    {#blank#}5{#/blank#} Nothing brings you back on track like a good laughter. It is the most powerful antidote(良方) to stress and it brings joy into your life. Laughing brings people together and drives away all stress-related problems as if they never existed. It is absolutely the best medicine there is, and it will keep you both physically and emotionally healthy.

A. Laugh it off.

B. Take some medicine.

C. As you walk, remember to look up.

D. Reading may also help you sleep better.

E. Your hobby could be reading books, or even writing one.

F. But most importantly, it can affect our physical and mental health.

G. The conversation with a close person will immediately make you feel better.

    According to a recent study published in Journal of Consumer Research, many people believe that healthy food must be more expensive than unhealthy food. In fact, the study's researchers found that a high price tag will even convince consumers that a certain food is healthful.

    According to Rebecca Reczek, coauthor of the study, the purpose of the study was to examine a popular belief. Sometimes the belief can be true: Organic produce and wild caught seafood typically cost more money. But other times, the nutritional value of food ranks all the same.

    In one experiment, Reczek's team gave a group of participants a new food product called "granola bites". Some participants were told the product was very healthy. Other participants were told the bites had little nutritional value. Participants who were told the granola bites were good for them rated the snack as more expensive than the participants who thought the bites were unhealthy.

    In another experiment, participants were given a health food bar labeled as "the healthiest protein bar on the planet". Some participants were told the bar cost just D|S0.99, others were told the bar was D|S4. And here's what happened: The people who were given the "cheaper" bar needed to read a lot more reviews about the product when it was priced at a lower price point in order to trust that it was healthy.

    The idea that we all believe healthy food needs to be more expensive works against us. All food companies need to do is push up the price to convince us.

But Reczek said, "When we shop, we don't have to be led astray. We can compare nutrition labels and we can do research before we go to the grocery store. We can use facts rather than our intuition (直觉)"．

    A so-called “smart drug” intended to improve people's cognitive (认知的) function to protect the brain from altitude sickness.

    Visiting high-altitude sites for work, spot, religious pilgrimages and military can result in cognitive effects, including memory loss and attention difficulties. There's little you can do to prevent these symptoms except acclimatize -but this takes time and doesn't always work. A drug called oxiracetam might be the answer.

    ShengLi Hu at the Third Military Medical University, Chongqing, China and her colleagues studied the performance of male military personnel at altitude. All lived in towns around 1,800 meters above sea level, During the study, they spent eight days at this altitude and then climbed for three days to reach 4,000 meters, where they stayed for up to a month.

    Twenty participants took oxriacetam three times a day for the first 15 days of the study, while another 20 received no intervention. The man did tests of attention and memory at the start and end of the study and 20 days in, by which time they had been at 4,000 meters for nine days.

    While all the participants experienced a drop in cognitive ability at 4,00 meters, those who took oxiracetam showed a much smaller drop than the control group.

    The team found that at high altitude the brain stem, which plays a critical role in supporting basic living functions, received blood at the expense of areas responsible for more advanced cognitive functions. But in people who took oxiracetam, blood flowing throughout the brain rose, thus offering more oxygen to these areas. This may be how the drug seems to lessen cognitive problems like with low oxygen.

    It isn't yet known whether diverting blood in this way could have negative effects in the long run. "The results are striking and imply that oxiracetam may be beneficial for helping to relieve cognitive ability decline caused by altitude." says Timothy Hales at the University of Dundee, UK.

    From the first use of the rocket to carry satellites into space to the setting up of space stations, human beings have been putting great effort into space research. And so far, we have achieved many successes. But there are still numerous tasks in front of us and we should not stop trying to progress.

    The international space station （ISS） is an important step we should take in space exploration. It is not only helpful but also essential. It provides a proper space environment for many experiments that we have wanted to do for a long time. It is also a base for the observations of the earth and the universe. It could also be an important base for later travel to the moon and Mars. In a word, if we want to explore space more, the first thing we should do is to set up a space station.

    As the space station costs a lot of money, it is hard for one country alone to establish one. The USA seem to be the only country that has the ability to build a space station alone, and it has tried to do so, but not very successful. So it aggregated many other countries to work on it together. Though it is still extremely expensive, it is much cheaper than doing it alone. It is really a job that needs everyone's effort and will benefit everyone.

    Led by the U. S. and Russia, the ISS is a joint project between six space agencies involving 16countries. Called the greatest achievement in human cooperation, the ISS has come to the end of a ten﹣year's hard work in construction. China has applied for participation in （taking part in） the project many times. Unfortunately all the applications were rejected, which drove China onto the path of independent development. As the Long March Ⅱ﹣F/T1 carrier rocket blasted off （leave the ground） and successfully carried the Tiangong﹣1into space on September 29, 2011, China takes a big step toward its Space Station Era.

    Some West media suggested that the successful launch of Tiangong﹣1 would disturb the balance of global space power, raising concerns about "China threat". China's space project is not designed for military purpose but for developing space technology to explore space resources and make use of them for mankind's well﹣being.

    Studying the DNA of 300 mice has flagged up genes which have been linked to hereditary (遗传的) sight loss for the first time. Researchers say because mice's genes are so similar to humans', their findings could lead to the treatment of more genetic diseases.

    Scientists at the University of California, Davis studied information from a data bank of mice's genetic material. They found 347 genes linked to eye problems, with just 86 of them having been studied in the past.

    Only around 50 to 75 percent of hereditary eye diseases in human can be explained with present science. The researchers believe these hundreds of new genes found in mice could be a key to explaining-and therefore being able to treat the other 25-50 percent.

    "This is extremely valuable for people with hereditary eye disease," said researcher Professor Ala Moshiri. "All researchers are going to start using these data. In the past, we knew the problem was there but we didn't know where to look. Now eye centers can call back patients and screen them for these new genes. We expected that more and more of these genetic diseases will be treatable." Also, the fact is that more than 60 percent of eye problems at birth are ones resulting from the baby's parents!

    Thanks to data from the International Mouse Phenotyping Consortium (IMPC), which is trying to work out what every single gene in a mouse is responsible for, with the aim of translating it to humans, scientists are moving closer to figuring out all genetic causes of blindness. To do this, scientists separate a single gene from other ones at a time and then observe what effect it has on the mouse for a long time. This has so far been done more than 7,000 times and has achieved great success. Researchers are now working alongside eye care centers in Texas and Iowa in order to compare the mice's genes to those of patients.