Ever feel like you've been hit on the head after a bad night's sleep? According to scientists, the thought isn't as unbelievable as it seems.

    A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head. The researchers said the healthy young men examined in the study showed a sudden increase in the same chemicals which indicate brain damage. Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion(脑震荡). He said, "What we found was their levels in the blood rose in the group that went without sleep for a night. This was not to the extent that would happen after a head injury, for instance, but it was still significant. During sleep, the brain cleans poisonous substances off itself."

    Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis could applaud his study. The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue, he explained. Benedict, whose study is published in the journal Sleep, added, "In conclusion, the findings of our experiment indicate a good night's sleep may be critical to maintaining brain health."

    A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago. Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours' sleep a night can lower the IQ the next day.

Learning a second language

    Nowadays, more and more people are learning a second language. So why should we spend time learning a second language?{#blank#}1{#/blank#}. Let us see.

    Career

    If your work involves regular contact with speakers of foreign languages, being able to talk to them in their own language will help you to communicate with them better.{#blank#}2{#/blank#} Knowledge of foreign languages may also increase your chances of finding a new job, getting a promotion or a transfer overseas, or of going on foreign business trips.

    Travel

    Being able to speak a foreign language, for example, the Japanese language, would benefit you greatly should you be traveling to Japan.{#blank#}3{#/blank#} If you are fond of tourism, then knowledge of the local language is a must-have to avoid bad experiences or discomfort.

    {#blank#}4{#/blank#}If you are a high school student who is interested in going abroad for further education, then you will have to learn the language of the country which you wish to move to. In some countries, being able to speak that country's national language is a must for students wishing to pursue (继续) education there.

    Personal growth

    Learning a second language can help in broadening one's horizons(视野). It can help in learning about the culture of that particular country{#blank#}5{#/blank#} Not only can you enjoy different forms of art and literature relating to the new language, but you can also meet new people, make new friends and develop long-lasting relationships.

A. Education

B. Challenge.

C. Is it really worth it?

D. This will save you a lot of trouble.

E. It can help you to make sales and get good deals.

F. And it can open the way for new interests and hobbies.

G. Could you be required to study a particular language at school?

    Dreams can be familiar and strange, fantastical or boring, but some dreams might be connected to the mental processes that help us learn. In a recent study, scientists found a connection between nap time dreams and better memory in people who were learning a new skill.

    In the study, 99 college students between the ages of 18 and 30 each spent an hour on a computer, trying to get through a virtual maze (逃宫). The maze was difficult, and the study participants had to start in a different place each time they tried, making it even more difficult. They were also told to find a particular picture of a tree and remember where it was.

    For the first 90 minutes of a five - hour break, half of the participants stayed awake and half were told to take a short nap. Participants who stayed awake were asked to describe their thoughts. Participants who took a nap were asked about their dreams after sleep and they were awakened within a minute of sleep to describe their dreams.

    Stickgold, a neuroscientist, wanted to know what people were dreaming about when their eyes weren't moving during sleep.Four of the 50 people who slept said their dreams were connected to the maze. Some dreamed about the music that had been playing when they were working; others said they dreamed about seeing people in the maze. When these four people tried the computer maze again, they were able to find the tree faster than before their naps.

    Stickgold suggests the dream itself doesn't' help a person learn, it's the other way around. He suspects that the dream was caused by the brain processes associated with learning.

    All four of the people who dreamed about the task had done poorly the first time,which makes Stickgold wonder if the dreams show up when a person finds a new task particularly difficult. People who had other dreams, or people who didn't' take a nap, didn't show the same improvement.

    I grew up in a house where the TV was seldom turned on and with one wall in my bedroom entirely lined with bookshelves, most of my childhood was spent on books I could get hold of. In fact, I grew up thinking of reading as natural as breathing and books unbelievably powerful in shaping perspectives (观点) by creating worlds we could step into, take part in and live in.

    With this unshakable belief. I, at fourteen, decided to become a writer. Here too, reading became useful. Every with writer starts off knowing that he has something to say, but being unable to find the right ways to say it. He has to find his own voice by reading widely and discovering which parts of the writers he agrees or disagrees with, or agrees with so strongly that it reshapes his own world. He cannot write without loving to read, because only through reading other people's writing can one discover what works, what doesn't and, in the end, together with lots of practice, what voice he has.

    Now I am in college，and have come to realize how important it is to read fiction (文学作品). As a law student, my reading is in fact limited to subject matter — the volume (量) of what I have to read for classes every week means there is little time to read anything else. Such reading made it clearer to me that I live in a very small part in this great place called life. Reading fiction reminds me that there is life beyond my own. It allows me to travel across the high seas and along the Silk Road，all from the comfort of my own armchair, to experience, though secondhand, exciting experiences that I wouldn't necessarily be able to have in my lifetime.

    After photographer Monni Must's daughter Miya died, the sad mother adopted her black dog, Billy Bean. As Billy became increasingly weak, the thought of its dying was just more than Must could handle. So she decided to clone the dog. “I feared everyone was going to forget Miya," she said, "and my other daughters thought I had completely lost my mind."

    Billy's cells were shipped to ViaGen Pets, a Texas company that provides the cloning service. With more than $50,000, Must picked up a new puppy. "The dog has a real soul and is everything my daughter was—fun, social and kind," she said. "I feel that I still have that touchable connection and not just a spiritual connection.”

    Cloning animals is hardly new. But the recent news that singer Barbra Streisand had cloned her dog grabbed international headlines. People for the Ethical Treatment of Animals(PETA) president Ingrid Newkirk issued a statement saying she would love to talk her out of cloning, noting that millions of wonderful dogs are getting old in animal shelters every year or dying in terrifying ways when abandoned.

    Normally, a doctor takes a tissue biopsy(组织活检), a piece of skin and muscle about the size of a pencil eraser, from the dog. The next step is to take an egg cell from a donor dog, remove the egg's nucleus, and insert DNA from the pet to be cloned. When an embryo(胚胎)develops, it is transplanted in the body of a mother dog.

    In the basic cloning procedure, scientists take an entire adult cell and put it into an egg that's been relieved of its own DNA. The resulting embryo is a clone. However, in many animals, only one in 100 cloned embryos ever leads to a live birth. Some embryos die in the IVF dish or in the mothers bodies. Of those that are born, a few suffer from abnormalities and quickly die. Besides, pet cloning doesn't mean copying everything of your beloved pets.

    UK-based swimming pool manufacturer (制造商) Compass Pools has announced plans for the world's first 360-degree infinity (无限) pool. Titled Infinity London, the pool would contain 600,000 liters of water, and would sit at the top of a 55-story hotel.

    According to Compass Pools' plan, the pool would feature transparent (透明的) walls and floor, offering views across London's skyline and down into the hotel below. These walls would be made of cast acrylic, a material chosen to make sure that the material is completely clear.

    The main problem with designing the pool was how to make sure entry or exit from the pool without affecting the view. Speaking about this design, Compass Pools' technical director and designer Alex Kemsley explained，"Normally a simple ladder would suffice, but we didn't want stairs on the outside of the building or in the pool as it would spoil the view – and obviously you don't want 600,000 litres of water running down through the building either. The solution is based on the door of a submarine, coupled with a rotating spiral (螺旋的) staircase which rises from the pool floor when someone wants to get in or out."

    Take a look at early models of how the pool might look in the gallery above. At present, no contract has been made but building work could begin as early as 2020.