“Croeso I Gymru!,” If you don't know what this means, read on to find out more.

    When you cross over the border from England into Wales, you don't have to show your passport but you do notice a difference immediately. All the road markings and signs are shown in two languages — English and Welsh (威尔士语）. Not all visitors to Britain know that other languages are spoken here. There's the Gaelic (盖尔语) language in Scotland and a few people speak Cornish (康沃尔语）in the southwest of England, but the most widely spoken language in the UK besides English is Welsh.

    Perhaps the first Welsh word you^'ll see on the road into Wales is ARAF. There's a helpful English translation next to it — SLOW. As you can see, Welsh looks quite different from English. It sounds very different, too. Welsh looks and sounds so different from English because it's a Celtic language. Celtic cultures still exist around the edges of the UK — in Wales, Scotland and Northern Ireland and also in parts of France. For hundreds of years, almost everyone in Wales spoke Welsh, but nowadays there are about 600 thousand Welsh speakers — around 20% of the population.

    So is Welsh dying out? Not at all! Nowadays, all school children in Wales study Welsh and many choose to go to an all Welsh-speaking school. You can get public information in Welsh, speak Welsh in court or take a course at university in Welsh. People surf the Internet in Welsh, keep up with friends on Facebook and write blogs in Welsh.

    By the way, ^“Croeso I Gymru!" means “Welcome to Wales!” 一 I hope you'll be able to visit it one day.

    I was a shy girl. I didn't even like to answer the telephone for fear I'd have to talk to somebody I didn't know. I enjoyed the loneliness of exploring nature. However, at school I had to spend all day in the company of others. My escape was reading. I spent a lot of time studying and was rewarded with good grades. My only failure was Spanish—I'd get all. As on my written work and tests, but Ds and Fs on the spoken part.

    Eventually I went to college. During my third year of college, I had enough of being shy and determined to change my outlook and behavior. One day while at school, I noticed an advertisement for positions on the local classical music radio station. I had grown up listening to classical music, and I could easily pronounce names such as Tchaikovsky, Albinoni, and Chopin.

    I had absolutely no background in radio, and absolutely no hope of getting the job. The idea of talking to thousands of listeners in “radio land” terrified me. However, I luckily survived the interview. I was given brief descriptions of symphonies（交响乐）and a public service announcement to read, and a list of composers' names to pronounce. It wasn't hard for me. I left the recording session（录音时段）with a sense of relief and a sense of accomplishment. About two weeks later I actually landed the job. It was a challenging job, but I grew to enjoy it greatly. I began to feel comfortable talking to people.

    Although I now spend many hours each week talking with people, I'm still basically a quiet person. Perhaps it is my soft voice and my quiet nature that helps draw people out as they respond to my questions as I interview them. My former shyness is a fortune, as I can relate to people who feel discomfortable when they talk to newspaper reporters. I still enjoy moments of loneliness and the peace found in nature. But I'm also glad I decided to make a change in my life that has opened many doors and opportunities that I never knew existed.

    Tourism wasn't as important as it is today. In the past, only people with a good deal of money could travel on holidays to other countries. More people travel today than in the past because there is a growing middle class in many parts of the world; that is to say, people now have more money for travel. Special plane fares(费用) for tourists make travel less expensive and more attractive than ever before. One person doesn't travel for the same reason as another. But most people enjoy seeing countries that are different from their own. They also like to meet new people and to taste new food.

    Tourism causes many changes in a country and in people's lives. People build new hotels and restaurants and train native men and women as guides to show visitors interesting places. There're new nightclubs and other amusements. International tourism is clearly a big business.

    David Cameron is urging today's youngsters to abandon French to concentrate on the tongue of the future—Mandarin(普通话)。

    Cameron said: "I want Britain linked up to the world's fast-growing economies. And that includes our young people learning the languages to seal tomorrow's business deals.”

    "By the time the children born today leave school, China is to be the world's largest economy. So it's time to look beyond the traditional focus on French and German and get many more children learning Mandarin.” To strengthen his message , he quoted Nelson Mandela—the former president of South Africa who said "If you talk to a man in a language he understands that goes to his head; if you talk to him in his own language that goes to his heart.”

    Cameron said that a partnership between the British Council (英国文化协会) and Hanban will double the number of Chinese language assistants in the UK by 2016 and provide increased funding to schools of offering Mandarin as a language choice. In a development of the UK—China School Partnership programme , funding will also be provided for 60 headteachers to make study visits to China in 2014.

    In recent research the British Council found only 1% of the adult population speaks Mandarin to a level that allows them to conduct a basic conversation. Just 3,000 pupils in England, Wales and Northern Ireland entered for Chinese languages GCSEs in 2013, putting it far behind the traditional choices of French with 177,000, Spanish with 91,000 and German with 62,000 entrants(加入者), as well as Urdu, Polish and Arabic.

    Professor Dame Helen Wallace, the British Academy's foreign secretary, said, " a lack of qualified teachers could be a barrier to improve its popularity.”

    Laura Chan, one of the co—founders of a bilingual Mandarin—English primary school, said the prime minister's announcement was good news for the status of Mandarin. She said, "It's a great help. It will increase people's awareness of Mandarin as a language they can learn.”

    Scientists have found an unexpected use for virtual reality headsets (耳机). The devices (装置), widely used by computer gamers, show pictures that can be used to test the navigational (导航的) skills of people, who were thought to be at risk of dementia (痴呆). Those who do worse in the tests will be the ones more likely to develop Alzheimer's disease later in life, scientists now believe.

    The discovery that the loss of navigational skills was associated with Alzheimer's was made several years ago by Dennis Chan and his colleagues based at several centers in the UK. These studies used computers to test navigational tasks. But now scientists plan to take their tests to a new level with the use of the virtual reality headsets in which wearers are placed in man-made environments through which they must navigate.

    Around 300 people, aged between 40 and 60, will be arranged to participate in the study. Some will have a gene that puts them at risk of the condition or will come from a family with a history of Alzheimer's. Not all will certainly be affected by the disease, however. Chan's project aims to find out who will. Wearing the headsets, participants will be asked to navigate their way through a series of different environments and then remember the details.

    Researchers recently pointed out the significance of a tiny area of the brain known as the entorhinal cortex (an important memory center in the brain). It acts as a center in a widespread brain network that controls navigation. This now appears to be the first part of the brain that seems to be easily harmed by Alzheimer's.

    The goal of the work is to help people as they develop the disease. "So far, drug trials for Alzheimer's have been applied when people have already got dementia, by which time considerable damage to the brain has already occurred," Chan told the Obsenver. "If we can develop drugs and use them earlier, for example, before the disease has spread beyong the entorhinal cortex, then this would have the potential to prevent the dementia."

The periodic table of elements is a common sight in classrooms，campus hallways and libraries. The mode periodic table arranges the elements by their atomic numbers and periodic properties（周期性）. Several scientists worked over a century to assemble the elements into this format. 

In 1789，French chemist Antoine Lavoisiertried grouping the elements as metals and nonmetals. Forty years later，German physicist Johann Wolfgang Dobereiner observed similarities in physical and chemical properties of certain elements. He arranged them in groups of three in increasing order of atomic weight and called them triads，observing that some properties of the middle element，such as atomic weight and density，approximated the average value of these properties in the other two in each triad. 

A breakthrough came with the pu blication of a revised list of elements and their atomic masses at the first international conference of chemistry in Karlsruhe，Germany，in 1860. They concluded hydrogen would be assigned the atomic weight of 1 and that the atomic weight of other elements would be decided by comparison with hydrogen. For example，carbon，being 12 times heavier than hydrogen，would have an atomic weight of 12. 

In 1869，Russian chemist Dmitri Mendeleev created the framework that became the moder periodic table，leaving gaps for elements that were yet to be discovered. Mendeleev predicted the properties of some undiscovered elements and gave them names such as"eka-aluminum"for an element with properties similar to aluminum. Later "eka-aluminum"was discovered as gallium. 

German chemist Lothar Meyer produced a version of the periodic table similar to Mendeleev's in 1870. He left gaps for undiscovered elements but never predicted their properties. The Royal Society of London awarded the Davy Medal in 1882 to both Mendeleev and Meyer. The later discovery of elements predicted by Mendeleev verified（证实）his predictions and his periodic table won universal recognition. In 1955 the 101st element was named mendelevium in his honor. 

On UNESCO website，it wrote，"The Periodic Table of Chemical Elements is more than just a guide or catalogue of the entire known atoms in the universe；it is essentially a window on the universe，helping to expand our understanding of the world around us. "