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    Have you ever wondered why the roots of the plants always know which way to grow—into the soil but not above it? Some British scientists have recently solved this mystery.    

      It turns out that roots have special hairs that tie them into the soil and help them grow their way past obstacles, a team at the John Inners Center in Norwich reports in the February 29 issue of Journal Science.

    "The key is in the fuzzy(有绒毛的) coat of hairs on the roots of plants," says professor Liam Dolan. "We have found a growth control system that enables these hairs to find their way and to become longer when their path is clear."

    Root hairs explore the soil in much the same way a person would feel their way in the dark. If they come across an obstacle, they make their way around until they can continue growing in an opening. I the meantime, the plant is held in place as the hairs grip the soil.

    The hairs are guided by a clever chemical trick. A protein(蛋白质) at the tip of the root hairs called RHD2 helps them to take calcium(钙) from the soil. Calcium makes the hairs grow, and produce more RHD2, and take more calcium.

    But when an obstacle blocks the hair's path, or the hair reaches the surface of the soil, the cycle is broken and growth starts in another direction.

    This system gives plants the flexibility to explore a complex environment and to live in even the most unpromising soils, says Dolan.

    In poor soils such as in parts of Australia and Africa, native plants have adapted by producing enormous numbers of root hairs. A better understanding of this adaptation will allow scientists to develop hairy rooted crops that can grow in unfriendly environments.

    According to Dolan, "Research in the John Inners Center is taking a breeding approach(育种方法) to increase hair length in wheat but it will be some time before new cultivars(栽培变种) are developed."

    Camping wild is a wonderful way to experience the natural world and, at its best, it makes little environmental influence. But with increasing numbers of people wanting to escape into the wilderness, it is becoming more and more important to camp unobtrusively (不引人注目地) and leave no mark.

    Wild camping is not permitted in many places, particularly in crowded low—land Britain. Wherever you are, find out about organizations responsible for managing wild spaces, and contact them to find out their policy on camping and shelter building. For example, it is fine to camp wild in remote parts of Scotland, but in England you must ask the landowner's permission, except in national parks.

    Camping is about having relaxation, sleeping outdoors, experiencing bad weather, and making do without modem conveniences. A busy, fully—equipped campsite (野营地) seems to go against this, so seek out smaller, more remote places with easy access to open spaces and perhaps beaches. Better still, find a campsite with no road access; walking in makes a real adventure.

    Finding the right spot to camp is the first step to guaranteeing a good night's sleep. Choose a campsite with privacy and minimum influence on others and the environment. Try to use an area where people have obviously camped before rather than creating a new spot. When camping in woodland, avoid standing dead trees, which may fall on a windy night. Avoid animal runs and caves, and possible homes of biting insects. Make sure you have most protection on the windward side. If you make a fire, do so downwind of your shelter. Always consider what influence you might have on the natural world. Avoid damaging plants. A good campsite is found, not made—changing it should be unnecessary.

    Recently, the Oxford English Dictionary, or OED, added about 1,000 words and new definitions to its website. The changes are to help users understand a mix of terms, some dating back many centuries. The additions include words such as "brencheese", "deathshildy" and "hip-pop".

    The new entries are part of the company's update to oed.com, its searchable online dictionary for paid members. The OED makes changes to the website four times each year. But the latest print version has been in process since the year 2000, and may not be ready for 10 more years. That information comes from Katherine Connor Martin, who heads the company's dictionary operations in the United States.

    Usually, the OED watches usage of a word for at least 10 years before deciding whether to add a new entry, new definition or word related to an existing entry, she said. This general rule, however, is sometimes not followed. That is what happened with "tweet", a word that the OED added far before the 10-year mark. Other times, the company adds words that are very old, but were not included in the dictionary in the past.

    “It's funny because we talk about new words, but many of the words we add are already obsolete. It's just that they were never in the dictionary before," Martin told the Associated Press.

    That is the reality, she said, of a historical dictionary trying to put more than 1,000 years of English into books that already have over 855,000 entries. So, you get "brencheese", a rarely used term for when bread and cheese are eaten together. The word dates back to the year 1665. The word "deathshildy" is from Old English. It means someone who is guilty of a serious crime and condemned to death.

    The website defines the term "hip-pop" for music that combines parts of hip-hop and popular music. The OED discovered the term “hip-hip pop” was used in a 1985 story from a Pennsylvania newspaper. It noted that the term "hip-pop" appeared in a 1991 U. S. newspaper report about the rap artist M.C. Hammer.

    The website has added several other terms related to modern culture. They include three popular terms: "binge-watching", "spoiler alert" and "microaggression".

    Here are a few other new entries if you long to read on.

    There is a cry of anger, and a tennis racket crashes to the ground. Jake, age 7, has just lost another match and is now in tears beside the court. His sister Sally, just one year older, looks at her mother and rolls her eyes: it is hard to enjoy winning when this keeps happening. It is not an unusual situation, and it is one reason why many people argue that competition is bad for children. However, the truth is that competitive games are a valuable preparation for adult life.

    Games with winners and losers give children the chance to experience life's ups and downs. Take Jake, for example. Even though he is unhappy now, he will probably be smiling and laughing with his sister in a few minutes, just like the last time this happened. Gradually, he will learn that the world does not end when you lose a game. Eventually, he may even be able to lose with a smile on his face. This is an important lesson. Not everything in life goes the way you would like, and it is important to know how to handle disappointment when it occurs.

    Children who participate in competitive games develop qualities that allow them to succeed in the complex world of adult life. For example, one of the missions of the Youth Olympic Games is to inspire young people to adopt the Olympic values, which include striving, determination and optimism. Competition creates a desire to do better. Children have to learn to succeed in a competitive atmosphere in order to take advantage of opportunities in the future. Although it is possible to win by chance occasionally, people who win and keep winning work very hard to achieve their success.

    On the negative side, there are those who will say that competition actually encourages some values, which does happen. It is common to see sports competition in which the desire to win has replaced the desire to have fun. You may even see very young children playing violently—like the superstars they see on TV. While the bad behavior of young athletes is troubling, the problem is not the competition itself. In reality, the blame lies with the professional players who are bad role models for these children. In fact, a recent study of young athletes by the school of Physical Health Education at the University of Wyoming showed an improvement in mood after exercise, athletes were less depressed or tense.

    Of course, there are parents who argue that children of Jake's age are too young to handle the pain of losing. But whether we like it or not, adult life is very competitive, and keeping children away from competition does them more harm than good. If children do not learn how to compete, they will be defeated by people who can. It is an unfortunate fact of life: whether ten or a hundred people want the same job, there can be only one winner. Wouldn't you want your child to be that person?

Brushing your teeth twice a day should keep the dentist away. But if a group of scientific researchers have their wish, it will make the rest of your body healthy too. A toothbrush that checks blood sugar and bacteria while you brush is currently in development in the USA. It is one of many gadgets (小器械) proposed by engineers and doctors at the Center for Future Health in New York.

The gadgets seem fanciful, but the basic principles are simple. The gadgets should make it easy for people to detect illness long before it strikes and so seek treatment far earlier than normal. Instead of relying on hi-tech hospitals, the emphasis (重点) is shifted to the home and easy-to-use gadgets. In the long run, the technology may even prevent illness by encouraging us to lead healthier lives.

Intelligent bandages are a good example. Powerful sensors within the bandage could quickly identify tiny amounts of bacteria in a wound and determine what medicine would work best. The cut could then be treated instantly.

The biggest development is melanoma(黑色素瘤) monitor designed to give early warnings of cancer. It could be used to take a picture of your body each week, and then compare it to previous images. If a problem is found, the system would advise you to get a check-up.

If all this sounds worrying, then help is at hand. Experts are also working on a "digital doctor", complete with a comforting bedside manner. A standard computer would be able to understand your voice and answer questions about your symptoms in plain English and in a way which could calm your nerves.

Stress is no sweat either. A portable communication aid could recognize certain phrases and tones and let you know when you are about to lose your temper. The software would also suggest ways of keeping your cool.

Researchers are still struggling, however, with making the technology cheap and simple enough for the household user. That is going to be the difficult part.

Nobody says high school and college are easy. Studying is difficult, as is memorizing information for a test. Fortunately, there are books that can help to make dealing with school easier.

Unlimited Memory by Kevin Horsley

Do you have trouble remembering everything you're studying? Feel like you have too much on your plate? Unlimited Memory by Kevin Horsley may be for you. It's a bestseller in memory improvement. This book has strategies to help you learn faster while also teaching you to become more productive. Of course, having a good memory comes in handy outside of the classroom as well. Really, this is a great book for life in general.

Student ^fs Guide to Writing College Papers by Kate L. Turabian

Many students reach college and find that essay writing in college is very different from that in high school. Whether this is the case for you or you just want to improve your writing skills, you'll want to check out Student's Guide to Writing College Papers. It's available on Kindle or in hardback or paperback forms. Right now, this one is its fourth edition. The book covers writing your actual paper, citing sources(引用来源), and style. Even English majors can find a lot of helpful tips in this book.

On Course by Skip Downing

It is another book you'll want to check out. In its eighth edition, the book provides you with self-assessment tools to help you identify what you need to change for academic success. It contains guided journal entries（分录）to help you with responsibility, self-management, self-awareness, learning and self-esteem.

How to Become a Straight A Student by Cal Newport

The book will teach you different approaches and strategies to help you score better but spend less time on studying, with a focus on studying smarter, not harder. It's available on Kindle and in audiobook(有声读物)and paperback forms.