Can exercise during childhood protect you against memory loss many decades later?Exercise early in life seems to have lifelong benefits for the brain,in rats at least.

     “This is an animal study,but it shows that physical activity at a young age is very important—not just for physical development,but for the whole lifelong track of cognitive（认知的）development during ageing,”says Martin Wojtowicz of the University of Toronto,Canada.“In humans,it may delay the appearance of Alzheimer's symptoms（阿茨海默氏症）,possibly to the point of preventing them.”

    Wojtowicz's team divided 80 young male rats into two equal groups,and placed running wheels in the cages of one group for a period of six weeks.Around four months later—when the rats had reached middle age—the team taught all the rats to connect an electric shock with being in a specific.When placed in the box,they froze with fear.

    Two weeks later,the team tested the rats in three situations: exactly the same box in the same room,the same box with the room arranged differently,and a completely different box in a different room.

    The rats without access to a running wheel when they were young now froze the same percentage of times in each of these situations,suggesting they couldn't remember which one was dangerous.But those that had been able to run in their youth froze 40 to 50 percent less in both changed box settings.

    "The results suggest the amount of physical activity when we're young,at least for rats,has influence on brain and cognitive health—in the form of better memories—when we're older,"says Arthur Kramer of Northeastern University in Boston,who has found that,in humans,exercise promotes the growth of new brain cells.

    Spend any time in London, England's capital, and you'll quickly gather that it's a multicultural (多元文化的) community. Look around at your fellow passengers on the Tube（地铁）or the bus. They're of every skin color and dress differently to one another. Listen, and you'll hear many other languages besides English spoken. Some of these people, no doubt, will be tourists who are in London to see the sights. But others – in fact probably most – will be living their lives there, along with millions of others.

    Along with white British people, there are Britons from, or with parents and grandparents from, the Caribbean, India, China and most other places. This makes London a fascinating place in which to live. The reason is that when people settle in a place, they don't just buy a house and live there, but bring aspects of the culture of their “old country” with them.

    The most visible sign of this is the number of restaurants offering dishes from different parts of the world. In a city in which it's estimated 250 different languages are spoken, you can expect a similarly wide range of foods to be available. You would expect in one of the world's leading cities to encounter(遇到) French, Italian, Chinese and Indian eateries. But in London you'll also find Polish, Patagonian and Palestinian restaurants.

    However, London's multiculturalism isn't just about food. Many types of people are gathered in one space, but the way they live differently shows in that space. They worship(崇拜)differently, for one thing. Alongside the famous old English churches by Nicholas Hawksmoor and Christopher Wren – responsible for one of the capital's most famous landmark, St Paul's Cathedral—you'll find mosques(清真寺), temples and synagogues (犹太教堂).

      London even speaks its own special kind of English. Language experts created the term “Multicultural London English” to identify the dialect of English that appeared at the end of the last century.

    All of this makes London a very surprising and varied place to call your home. But, in a way, this has long been true. In the 18^th century, the compiler(编纂者) of the first English dictionary, Samuel Johnson, once said: “ He who is tired of London is tired of life.”

    Elephants might be the most well-known and well-loved animal in African wildlife. But conservation (保护) of the African elephant still faces special difficulties. While the elephant population is half of what it was 40 years ago, some areas of Africa have more elephants than populated areas can support. That's why AWF scientists are studying elephant behavior, protecting habitats and finding ways for humans to live peacefully with elephants in Africa.

    Years ago, overhunting and the ivory trade were the biggest threats to elephants' survival. Luckily, ivory bans (禁令), hunting rules and protected areas protect elephants from these dangers today.

    The 21st century brings a different challenge to elephant conservation—land-use. Elephants walk across borders and outside parks and other protected areas. So they often destroy crops, causing conflicts (冲突) between local farmers and these big animals.

    Successful conservation strategies must allow elephants to walk freely in their natural habitats while reducing conflicts between elephants and local people.

    AWF researchers are searching for a way to give both elephants and people the space they need. The AWF is collecting information on elephant habitats and behavior. The information they gather will help to develop the widest possible space for elephants.

    The AWF is helping elephants by protecting their habitats. And they also work with local farmers to improve their life in order to encourage them to protect rather than destroy elephants.

    When first entered, Vanak Restaurant does not look like much of a restaurant, but once the pleasant smells of kabob (烤肉串) hit the senses, you are incapable of calling it anything less.

    Owned by a local couple, this Persian restaurant has an inviting, homelike atmosphere that many restaurants lack.

    The space is small with only a few dining tables and nearly no decoration, but the environment is truly charming.

    Lying in a hardly noticeable street corner, the restaurant still attracts all customers, especially those experienced in the delights of Middle Eastern cooking.

    A common sight is that of old Persian men sitting in the corner talking loudly about world topics, watching news events on TV, drinking a black tea known as Persian chai, and reading local Persian newspapers all the while trying to finish off their plates piled with food.

    The variety of food at the restaurant is limited, but the amount of each dish is fairly large. Most of the meals can serve two people and are under $10, so not only is it affordable but practical as well.

    The food especially appeals to health-conscious eaters because each dish is very healthy, made with limited fat and oil and served straight off the grill (烤肉架).

    The main dish that the restaurant is popular for is its kabobs, which are different styles of grilled meat.

    One delicious and extremely healthy dish is the Joojeh Kabob, which is made of grilled chicken pieces served with either rice or bread. Another great kabob is the Chelo Kabob, a kabob consisting of grilled beef.

    Although the restaurant is small, the atmosphere and the food is delicious. It is a place that should not be overlooked.

    Florida is a state located in the southeastern region of the United States. It is one of the most visited states in the country and the sunshine state attracts millions of visitors each year. Are you planning a vacation to it? Here our travel guide may help you.

    La Nouba at Walt Disney World Resort

    Duration: 90 minutes

    Location: Orlando, Florida

    While you're in Orlando, spend a day at the theme parks with a Cirque du Soleil show at Downtown Disney, La Nouba is the meeting of two different worlds—the fantastic world of the circus (马戏团) people who wear bright colors and the boring world of the people living in big cities who wear dark, lifeless clothes.

    Kennedy Space Center

    Duration: Flexible

    Location: Orlando, Florida

    Spend a day exploring the attractive Kennedy Space Center, just 45 minutes from Orlando. Learn about the history of the US space program and watch beautiful IMAX films. Don't miss the chance to walk under a Saturn V rocket, and experience a real moonwalk!

    Sea World Orlando

    Duration: Varies

    Location: Orlando, Florida

    Spend a day at Sea World Orlando and come face to face with the ocean's most attractive sea animals. With several up­close meetings with killer whales, sharks and turtles, you'll feel the energy and excitement of all kinds of sea life.

    South Beach Cultural Food and Walking Tour

    Duration: 2 hours and 30 minutes

    Location: Miami, Florida

    On the South Beach Cultural Food and Walking Tour, you'll explore the Art Deco district of South Beach on foot and along the way, you'll taste a variety of foods that make South Beach such an internationally well­known food region.

    Price information：

    Click the link below to check price information on your preferred travel date. Our price is constantly updated.

    The cold and icy land that is the Eskimo's home is a dangerous one. The Eskimo once believed that to be safe from danger he had to obey taboos(禁忌). Taboos were rules that told him what he must do and must not do.

    The Eskimo had taboos connected with almost everything he did. He had to keep them in mind at all times. He believed that to break one would bring disaster. For the Eskimo, it was taboo to store reindeer(驯鹿) and seal (海豹) meat together. He could not even eat them on the same day. He believed the Goddess Sedna had separated the land animals from the sea animals. He thought bringing them together would cause the hunting to be bad.

    There were other taboos concerning animals. When a dead seal was brought into the house, the women had to stop working. They had to give its spirit a drink of water. If they did not, the spirit would be angered. It would keep other animals from being caught.

    When the Eskimo broken a taboo, he believed a black cloud formed around his head. He had to tell the others in the village what he had done. He thought that if he did not tell his neighbors, they would catch the black cloud. Then the whole village would have bad luck.