Good manners are important, but you can easily make a social blunder when you visit a foreign country, because sometimes good manners in one place are bad manners in other places.

    Suppose you visit some friends in Mongolia and they ask you to eat with them. What kind of manners do they want you to have? They want you to give a loud “burp” after you finish eating. Burping shows that you like your food. But in some other countries, if you give a loud “burp”, you are supposed to say, “Excuse me, please.”

    In many places people like to eat together. But in some parts of Polynesia it is bad manners to be seen eating together. People show their good manners by turning their backs on others while they eat.

    What are manners like in an East African town? The people try not to see you. When you are visiting a friend, he may not see you at all. If you are polite, you will sit down beside him. You will wait until he finishes what he is doing. Then he will talk to you.

    If you visit a friend in Arabia you should walk behind other tents until you come to his tent. If you pass in front of other tents, you will be asked into each one. The people will ask you to eat with them. And it is bad manners if you say no.

    Manners are different all over the world. But it is good to know that all manners help people show that they want to be friends.

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    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.”

    Many science fiction stories tell about explorers arriving in a new world. The explorers then use some kind of high-tech device to test for breathable air or signs of life. But here on Earth, science fiction is becoming reality through a new sampling technology called environmental DNA, or eDNA for short. Scientists can use it to identify rare species or estimate fish populations with just a little air or water.

    Environmental DNA can be used in two ways. One is to identify the creatures that live in a certain place. The other is to confirm the presence or lack of a specific creature.

    Caren Goldberg is one of the first biologists to take the technology from the testing stage to actually using it. She sees eDNA as a way to get answers more efficiently and with less destruction compared to traditional survey techniques. Until recently, scientists depended on snorkeling ( 潜水), netting or using an electric current to temporarily catch fish.

    This newer way to identify what lives in the environment is becoming popular around the world. Animal experts in Vietnam are using the eDNA to find the last, wild Yangtze giant softshell turtles. One researcher on the Caribbean island of Trinidad is using the sampling technology to find endangered golden treefrogs. In Madagascar, it is being used to identify amphibian(两栖动物)diseases.

    Ms Goldberg has used eDNA testing to confirm the local extinction (灭绝) of a leopard frog in the American state of Idaho. She has also been asked to document the spread of the New Zealand mudsnail in the state of Washington. The creature has been found in lakes and other waterways across the state.

    Scientists working with the technology say they do not expect robots to replace field biologists anytime soon. But the old-fashioned field work could soon be more targeted.

    There is a popular saying in the English language: "Sticks and stones may break my bones, but words will never hurt me." Well, that is not true. Unkind words, name-calling or even the so-called "the silent treatment" can hurt children as much as being physically hit, sometimes even more so.

    A recent study of middle school children showed that verbal(言语的) abuse by other children can harm development in the brain. The study was a project of researchers at Harvard Medical School in Massachusetts. Researcher Martin Teicher and his team studied young adults, aged 18 to 25. These young men and women had not ever been treated in a cruel or violent way by their parents. The researchers asked the young people to rate their childhood exposure to verbal abuse from both parents and other children. Then the researchers performed imaging tests on the brains of the subjects.

    The images showed that the people who reported suffering verbal abuse from peers in middle school had underdeveloped connections between the left and right side of the brain. The two sides of the brain are connected by a large bundle of connecting fibers called the corpus callosum. This was the area that was underdeveloped.

    The middle school years are a time when these brain connections are developing. So, unkind, hurtful comments from children or adults during this period have the greatest effect. The researchers tested the mental and emotional condition of all the young people in the study. The tests showed that this same group of people had higher levels of fear, depression, anger and drug abuse than others in the study.

    The researchers published their findings online on the American Journal of Psychiatry's website.

    Parents cannot control what other people say to their children, but they can prepare their children.

Located in southern Anhui Province, Mount Huangshan (黄山) covers {#blank#}1{#/blank#} area of 250 kilometers, of {#blank#}2{#/blank#} 154 square kilometers are scenic attractions. Its landscape features "four wonders" of imposing peaks, spectacular rocks, odd-shaped pines, and a sea of clouds. 

Mount Huangshan boasts 72 peaks, more than 1, 000 meters above sea level, with three main peaks rising majestically. They are both fascinating and {#blank#}3{#/blank#}(danger). Cliffs, stone forests, stone pillars, stone blocks and egg-shaped stones form the unique granite geomorphological(地貌的） scenery. 

The pines on the mountain are tall and have fascinating{#blank#}4{#/blank#}(shape). The famous Welcoming Guests Pine (Yingke Song) (1, 500 years old) and See-Guest-Off Pine have become a symbol of being faithful, unyielding(不屈的) and hospitable. More than 200 days each year on Mount Huangshan are misty and cloudy. The vapors coagulate(凝结）to form a sea of clouds. As the clouds cloak the mountain, they give a feeling of being in fairyland. 

Mount Huangshan has more than 400 famous scenic attractions of which 140 have been developed and opened to {#blank#}5{#/blank#}(tour). 

In 1990, Mount Huangshan went on both the world cultural {#blank#}6{#/blank#} natural heritage lists. Is it really so beautiful?

Hearing aids usually bring to mind images of ugly, ineffective devices mainly worn by the elderly. But this ill repute (恶名) is quickly changing, as they've recently taken a turn thanks to two innovators, Dr. Marco Vietor and Paul Crusius, who now lead the fastest-growing hearing aid company in the world-hear. com.

Hear. com's years of research led to the development of two game-changing hearing aids-the Silk and Styletto. These impressive devices pack cutting-edge (尖端的) technology in designs that are practically invisible. They also use a unique way that has been clinically (临床地) proven to deliver better-than-normal hearing so you can clearly understand speech in any environment. With additional features like Bluetooth and rechargeability, today's hearing aids are attracting even younger customers skilled in tech.

But hear. com knows it's not just about tech and design. They've put an enormous effort into the entire experience to make hearing care more accessible and more affordable. "Everyone should be able to hear well to live well," Crusius says. "And it's very individual. Each person's hearing loss is different and requires a personalized approach to find the best solution."

"We hear with our brains, not our ears. And it takes at least 30 days for our brain to adjust and relearn how to hear again with new hearing aids," Dr. Vietor says. "To guarantee your best outcome with hearing aids, we developed the industry's first 30-day program, Hearing Success Program, so customers have that extra level of care and knowledge to succeed."

And it's working. Hear. com has now helped more than 100,000 customers improve their hearing. Their A+ rating with the Better Business Bureau and 5-star rating on the customer review platform, Trustpilot, speaks for itself.

Hear. com's "customer first" approach also helps drive the company's success, encouraging employees to act like owners and put customers first. "We're investing heavily in shaping our company culture," Crusius says. "Individuals who work at hear. com say they are here to do more than a job. They're helping change lives all around the world."