In France, a man walks on what can only be described as a human-sized hamster wheel. The wheel moves around and around, as the man keeps walking. What is he doing? He is lifting a heavy object to the top of a tower the same way workers moved such objects 800 years ago.

    In the 13th century, workers did not have the 100-meter tall cranes they now use to build tall buildings. So they had to be creative and come up with simple machines to get their work done.

    The man on the large wheel is walking at a reasonable speed. The wheel turns and pulls a rope connected to a pulley(滑轮)at the top of the tower. Another rope tied to the pulley lifts supplies from the ground.

    This is just one way skilled craftsmen arc building a 13th-century castle without using modern tools. Crew have been working on the castle since 1997. It is being built in the Burgundy area of central France. Organizers expect the work to last another 10 to 15 years. That means it will take close to 30 years to finish the project.

    The crew are making progress at about half the speed of the workers from 800 years ago. That is because many of them are accustomed to using modern tools. When the crew use heavy chisels(凿子）and hammers to break rock, as they did hundreds of years ago, they are learning as they go. The goal of the project is to learn more about old building techniques in case they might be of use today.

    Clement Guerard, 44,is a stonemason; he cuts and builds with stone. He has been working on the tower for 17 years. He said one way he is able to work on something like this for so long is by forgetting “some of the pace of modern life", he is able to adapt to working by hand.

    Philadelphia, Pennsylvania w America's fifth largest city. Once a major American colonial city, it is the home of America's first library, its first hospital, and its first zoo. Now it is also the first US city to be named a World Heritage City. On November 6, 2015. Philadelphia joined more than 260 other cities that have been recognized for their influence on the world. These cities include Paris, France Florence, Italy and Cairo Egypt.

    "Today marks the start of a new and exciting chapter in the history of Philadelphia" remarked Philadelphia Mayor Michael Nutter when the announcement was made. “As a World Heritage City. Philadelphia is being officially recognized on the global stage for its wealth of contributions to the world. ”

    To be named a World Heritage City, a city be home to a UNESCO World Heritage site are selected for their universal value and significance. For Philadelphia, the site is Independence Hall.

    Independence Hall is where two of the most important documents, approved in US history - the Declaration of Independence and the US Constitution-were adopted. The Declaration of Independence, approved on July 4 1776, united the 13 former British colonies and declared them independent from British rule. The US constitution, signed in 1787, established the American democratic system of government. Democracy is a system of government in which the people elect their leaders. The Constitution later spelled out basic freedoms American citizens have.

    Philadelphia Deputy Mayor Alan Greenberger says the city's selection as a World Heritage City also reflects ta its educational, cultural, and economic achievements. The city is home to dozens of colleges and universities, and many museums, such as the Philadelphia Museum of Art.“Philadelphia has rightfully earned its place as one of the greatest cities in the world.” Greenberger says.

    I had a teacher who used to wake up in class by shouting: "The early bird gets the worm!" I say "let him have the worm". I hate food that doesn't stay still, and avoid Japanese restaurants for that very reason. Anyway, I stopped eating worms at the age of three, switching to regular breakfasts of cereal(谷物), to which I would add extra sugar.

    Recently I was thinking about early birds and the competitive spirit after receiving a letter from a reader in Malaysia: "My son deliberately throws away marks because he doesn't like to be top of the class. What shall I do?" Give him a round of "applause" for being smart! Actually many children in Asia tend to be the focus by performing better.

    Placed into a very competitive class when I was 11, I quickly learned the ideal position was second to last. The top three performers and the very last person are highlighted; the second-to-last contestant is INVISIBLE. And it's an easy position to get—just deliberately underperform at every test. I could do that. I once came second to last in eight straight sports day races. No one suspected anything. I was so invisible that I could have robbed a bank in my street and no one would have noticed.

    At the London Olympics a few months ago, badminton pairs from three Asian countries deliberately tried to lost matches to draw good lots in later rounds. It was funny to watch, but they were all thrown out for poor sportsmanship. What they really needed were acting lessons, their moves were so unconvincing. "Oops, I hit the ball in entirely the wrong direction."

    The other day, I took the children out and they raced for the car. "I'm first," said one. The second said: "First is worst, second is best." Together they sang at the last one: "And third's the one with a hairy chest."

    It struck me that the organizers of sports matches could use this song when people deliberately lost matches. "I lost," the delighted loser will say. The judges could still declare them winners, pointing to a new, optional regulation: "First is worst, second is best, third's the one with a hairy chest."

    Living abroad to study can certainly be an interesting experience but is that alone a good enough reason for spending years far away from home? To make the experience truly worthwhile, there has to be a goal behind the decision to study abroad. This may be a wish to perfect language skills in a foreign language environment, or a clever move in your career development. You must also consider the costs, not just of living and studying abroad, but of applying. Most universities now charge application fees for international students.

    If after considering these points you are sure that you want to apply to study abroad, your next step is to choose the right programme of studies. Research your choices and select carefully. You must do your homework well. Most universities have information online but you can also email and ask them to send you more details. You can find a lot of information on school ranking from education websites. But read carefully. Different universities emphasize different strengths. Don't just think about the university's reputation; look for the most suitable for your goals.

    Next, you must deal with a large pile of paperwork. This involves filling in application forms, preparing your school records, and getting reference letters. Reading the instructions and requirements of the universities carefully is of great importance. Sadly, many fine applicants get kicked out in the first round, simply because they don't follow the application procedure properly.

    Money is another important consideration. Some scholarships are provided by governments, others by schools and colleges. This information, again, can be found on the Internet. If you find a scholarship that is suitable for you, follow the application procedure carefully; the earlier you apply, the better your chance of getting it.

    All across the nation, in Americans' backyards and garages and living rooms, wild animals kept as pets live side by side with their human owners. It's believed that more exotic animals live in American homes than are cared for in American zoos. The exotic-pet business has drawn criticism from animal welfare advocates and wildlife conservationists alike, who say it's not only dangerous to bring wildlife into households but it's cruel and criminal. Yet the issue is far from black or white.

    The term exotic pet has no firm definition. It can refer to any wildlife kept in human households or simply to a pet that's more unusual than the common dog or cat. Privately owning exotic animals is currently permitted in a handful of states with no restrictions in America. Adam Roberts of Born Free USA keeps a running database of deaths and injuries caused by exotic-pet ownership: In Connecticut a 55-year-old woman's face was permanently disfigured by her friend's lifelong pet monkey; in Ohio an 80-year-old man was attacked by a 200-pound kangaroo；in Nebraska a 34-year-old man was strangled(勒) to death by his pet snake. And that list does not include the number of people who become sick from coming into contact with zoonotic(动物传染的) diseases.

    Some people see wild animals as pets as a way to connect with the natural world. Other exotic-pet owners say they are motivated by a desire to preserve threatened species. They believe climate change and human population growth could wipe out a species in record time, so having a backup population is a good idea.

    But some groups like Born Free USA and the World Wildlife Fund say that captive breeding(圈养) of endangered species by private owners—whether for commercial, conservation, or educational reasons—serves only to continue a booming market for exotic animals. That, in turn, results in a greater risk to animals still living in their natural habitat.

    Darwin noted that some human emotional expressions might have started as part of a physiological function: for example, exposing the teeth to bite food. The function, however, took on meaning and became a form of communication which signals anger.

    The same may be true for the animals. Baby monkeys cry for attention. They also cry to signal to an adult that they want to be carried.

    "Chimpanzees do make upset voice when they are being weaned (断奶) by their mothers or have lost their mothers or another individual, " says Anne Pusey, a professor at the University of Minnesota. "They whimper (呜咽) and cry and scream. When we hear these calls, the emotion involved seems obvious. However, they do not weep in the sense of producing tears. "

    The Iowan researchers can cause the same crying sounds by producing large decreases and then increases in blood flow. The blood flow also goes down when baby rats get cold. Thus, they conclude baby rats cry in the same way that we sneeze. Of course the rat baby could be crying because he's cold and wants his mother to know.