You can tell a lot about people by looking at their hair – not just whether they brush, spray or blow-dry. Scientists have found a way to use hair to figure out where a person is from and where that person has been. The finding could help solve crimes, among other useful applications.

    Water is central to the new technique. The liquid makes up more than half an adult human's body weight. Our bodies break water down into hydrogen(氢) and oxygen. Atoms of these two elements end up in our tissues, fingernails, and hair.

    But not all water is the same. Hydrogen and oxygen atoms can vary in how much they weigh. In the case of hydrogen, for example, there are three types according to their weights. Each type is called a hydrogen isotope（同位素）. And depending on where you live, tap water contains different isotopes.

    Can hair record this information? That's what James R. Ehleringer, an environmental chemist at the University of Utah, wondered. To find it out, he and his colleagues collected hair from hair stylists in 65 cities across the United States. Even though people drink a lot of bottled water these days, the researchers have found that people's hair has the same isotopes as found in local tap water. That's probably because people usually cook their food with the local water.

    Authorities can now use the information to analyze hair samples from criminals or crime victims and narrow their search for clues. For example, one hair sample used in Ehleringer's study came from a man who had moved from San Francisco to Salt Lake City. As his hair grew, it reflected his change in location.

    From roller coasters to adventure tours performances to experiments, there are plenty of exciting attractions in the UK. Here is our pick of the best attractions that children can visit.

    The Natural History Museum

Why go: This really is the grandfather of all London museums—the beauty of the building and the amazing exhibits. Look out for the whale skeleton(骨架) occupying the entry hall, but don't miss the largest piece of gold (or a model of it) in the minerals gallery. You can easily spend a day here—tasty steaks, sandwiches and pizzas. Try to avoid weekends, because the crowds are larger

    Best for: Children aged 5 and over. If time is limited, families should go quickly and directly towards the dinosaur gallery, because it's really wonderful.

    Details: Entry is free, although there is a charge for some temporary exhibitions

    Legoland

    Why go: Some 80 million Lego bricks have gone into the creation of this colourful park. There are thrilling rides and countless ways to spend money in shops. Yes, the queues can be long (unless you pay extra for the queue-jumping equipment, which is useful though it does not cover all rides)

    Best for: Legoland is aimed at children under10s, with pre-schoolers particularly well catered for in Duplo Valley

    Details: ￡32 per person; under 3s go free. 25 per cent discount for booking online more than seven days in advance.

Warner Bros. Studio Tour London —The Making of Harry Potter

    Why go: You've read the books, you've watched the films, but no Harry Potter fan will want to miss the chance to go behind the scenes at the film studios where all eight of the movies were made. Sharing the secrets behind the most successful film series of all time and yet still managing to keep the sense of magic alive, this studio tour gives visitors access to two locations filled with original sets and costumes

    Best for: Children aged 7 and over, and anyone with an interest in filmmaking

    Details: ￡39 adults; ￡31 children; under 4s go free

    It is one of the oldest magic tricks in the book—a magician locks a woman in a box, with her head and feet sticking out from either end, and saws (锯) it in half. But when she finally jumps out of the box, the woman is unharmed.

    This trick was introduced nearly a century ago. It has been around for some time, but it never goes wrong. Why is it so successful? The answer is simple: the human mind is easily fooled.

    Our brain processes the world around us based on information that sensory organs, including the eyes, pick up. For instance, when we see a cow or a horse standing behind a tree, we automatically “fill in” the part of the animal's body that is hidden from our sight. “So the brain is taking this kind of very sparse (匮乏的) information about the world and it's generating this rich world by filling in information,” Stephen Macknik, a scientist at the Barrow Neurological Institute in Arizona, US, told Science magazine.

    But since our brains are filling in the gaps, sometimes they get it wrong. They tend to be driven by our previous experiences and we expect things to go as they have in the past even if sometimes they do not.

    This tendency explains magicians' success in fooling people with well-known coin tricks. For example, when you see a magician throw a coin up and down in one hand and then fake a coin thrown to the other hand, you would naturally believe that the coin is in the other hand.

Apart from the information gaps, magicians also use the “blind spots” theory when doing their shows.

    The most well-known experiment demonstrating this theory is called the “invisible gorilla (大猩猩)”, in which volunteers watch a video of two basketball teams. They are asked to count how many times the teams wearing white shirts pass the ball. In the meantime, a person dressed as a gorilla walks onto the court. But shockingly, half of the viewers don't notice the gorilla, even when they appear to be looking directly at it.

    Magicians employ this tactic (招数), what they call “misdirection”, in almost every one of their acts. They direct our attention somewhere else using comedy and music, which can make us miss stuff during the performance.

    It had been a long winter. Bitter cold, snowy days had hit us again and again. On the warmer days there had been little sunshine, but only cold, icy rain. The sun had become such a rare sight that I had to look at a picture of it on my wall calendar from time to time to remember what it looked like. The grass had remained brown and dormant（潜伏的）in the grassland. My own backyard had turned into a muddy mess that tried to steal the shoes right off my feet as I walked on it. My heart ached and longed for spring, and my own good cheer had trouble rising up against the continuous, cold, gray days.

    The rain poured down on me as I walked my dogs, holding their leashes in my icy fingers. I looked up at the sky hoping to see the sun smiling down with its warm, golden face. But it was no use. It was then, however, that I saw it. It wasn't the smiling face of the sun in the sky but a little, yellow face peeking（微露出） through the mud. It was a tiny flower, and it filled my heart with hope and joy. I smiled and thanked God for this little sign that winter would soon be over and that spring would arrive. I felt my good cheer rising up at last and I promised God that I would share it with everyone I could.

    One day that tiny flower's seeds will fill the grassland with little, yellow faces smiling up from the ground. Its work will make this world a better and more beautiful place. May we all do the same. May we all shine our light and share our love even on the coldest and grayest days. May we all help to share a bit of spring in winter. May we all work to make this world better and brighter even when it is at its darkest.

    Many of us love July because it's the month when nature's berries and stone fruits are in abundance. These colourful and sweet jewels form British Columbia's fields are little powerhouses of nutritional protection.

    Of the common berries, strawberries are highest in vitamin C, although, because of their seeds, raspberries contain a little more protein (蛋白质), iron and zinc (not that fruits have much protein). Blueberries are particularly high in antioxidants (抗氧化物质). The yellow and orange stone fruits such as peaches are high in the carotenoids we turn into vitamin A and which are antioxidants. As for cherries (樱桃), they are so delicious who cares? However, they are rich in vitamin C.

    When combined with berries of slices of other fruits, frozen bananas make an excellent base for thick, cooling fruit shakes and low fat "ice cream". For this purpose, select ripe bananas for freezing as they are much sweeter. Remove the skin and place them in plastic bags or containers and freeze. If you like, a squeeze of fresh lemon juice on the bananas will prevent them turning brown. Frozen bananas will last several weeks, depending on their ripeness and the temperature of the freezer.

    If you have a juicer, you can simply feed in frozen bananas and some berries or sliced fruit. Out comes a "soft-serve" creamy dessert, to be eaten right away. This makes a fun activity for a children's party; they love feeding the fruit and frozen bananas into the top of the machine and watching the ice cream come out below.

    As computers become more popular in China, Chinese people are increasingly depending on computer keyboards to input Chinese characters. But if they use the computer too much, they may end up forgetting the exact strokes of each Chinese character when writing on paper. Experts suggest people, especially students, write by hand more.

    Do you write by hand more or type more? In Beijing, students start using a computer as early as primary school. And computer dependence is more widely spread among university students. Almost all their assignment and essays are typed on a computer.

    All the students interviewed say they usually use a computer.

    It's faster and easier to correct if using a computer. And that's why computers are being applied more and more often to modern education. But when people are taking stock in computers increasingly, problems appear.

    "When I'm writing with a pen, I find I often can't remember how to write a character, though I feel I'm familiar with it."

    "I'm not in the mood to write when faced with a pen and paper."

    Many students don't feel this is something to worry about. Now that it's more convenient and efficient to write on a computer, why bother to handwrite?

    Many educators think differently. Shi Liwei, headmaster of a famous primary school in the capital said, "Chinese characters enjoy both practical and aesthetic value. But those characters typed with computer keyboards only maintain their practical value. All the artistic beauty of the characters is lost. And handwriting contains the writer's emotion. Through one's handwriting, people can get to know one's thinking and personality. Beautiful writing will give people a better first impression of them."

    To encourage students to handwrite more, many primary schools in Beijing have made writing classes compulsory(必修的)and in universities, some professors are asking students to turn in their homework and essays written by hand.