You may know the Eiffel Tower as one of the most famous man-made monuments in the world, and you'd be absolutely right! Read on to learn about the history of the great Eiffel Tower.

    Travelers from around the world flock(蜂拥)to Paris, France, to visit the Eiffel Tower, making it the most visited paid monument in the entire world! In fact, in 2010, the Eiffel Tower welcomed its 250 millionth visitor!

The history of the Eiffel Tower

    The Eiffel Tower was named after the engineer Gustave Eiffel, whose company designed and built the famous monument. Construction began in January of 1887 and was completed in only two years. Their plan was to finish the tower in time to be the entrance arch for the World's Fair in 1889. This fair celebrated the 100^th anniversary of the French Revolution, which took place from 1789 to 1799.

The height competition

    Located on the Champs de Mars, the tower is the tallest structure in Paris. It was the tallest man-made structure in the world for 41 years until the Chrysler Building in New York surpassed(超过) it. Then the spire(塔尖) on the top of the tower was added, raising its height to 17 feet taller than the Chrysler Building. It is now 1,063 feet tall! There are two replicas(复制品) of the Eiffel Tower in the world: a half scale model at the Paris Hotel in Las Vegas and a full-sized monument of a similar (but not exact) design in Tokyo, Japan.

Three shades of wonder

    Some pictures make the Eiffel Tower look like a dark iron color. But it is, in fact, bronze. Not only that, but the tower is actually painted three different shades to make it appear even taller: darkest on the bottom and lightest on the top.

    I was asked in an e­mail about learning idioms in a foreign language. Maybe I am different from most people，but I do not bother with them. To me they are kind of dessert of language learning. They come at the end of a meal. Once you have filled up with the key words and phrases that are used in a variety of situations，then you can add a few idioms. And by that time, you will be able to pick them up naturally anyway.

    I find that many learners have trouble with idioms，as if repeating some very colloquial expressions is going to upgrade how they sound in a language. In fact, it is the opposite. Idioms are difficult to use correctly.

    Yes，occasionally you hear idioms and do not understand. But，in my experience，there are always situations where you do not understand. It is best to focus on the most important words，what they mean and how they are used. Certainly，it is best for a non­native speaker to stick to standard speech.

    Some teachers even try to teach the “real language”．Then you hear non­native speakers saying things like “I goanna”, “You wane” etc.

    You will learn all the idioms you need just by exposing yourself to the language. In general，you can save any phrase that you find interesting，and if that includes idioms，go to it. But I would not make any special effort to go after idioms. I，in fact，avoid them. If I come across something in Russian that strikes me as a particularly idiomatic use of words，I just leave it aside; do not even bother trying to learn it. If it keeps on appearing，then I will learn it.

    When was the last time you told someone they inspire you to go to work each morning?

    Teachers at Oak Park High School in Kansas City, Missouri, did just that this September, when they pulled individual students out of class to tell them just how much they appreciated them.

    The students' reactions, which were captured (捕捉) on video and shared on YouTube in a now-viral video, ranged from shy thanks to hugs and tears.

    “I have been challenged to find a student who makes me want to come to school every day,” says one teacher in the video, “and that's you.”

    Jamie McSparin, a teacher in charge of the school's academy program for at-risk sophomores （二年级学生）and juniors, posed the challenge, writes ABC News.

    “Initially when we pulled the kids out, they all thought they were in trouble,” McSparin told ABC News. “Any teacher-student interaction always seems to be negative (消极的), and that was something that bothered me, too. No matter if they're a good kid or a trouble maker or anything, they always thought they were in trouble,” she says.

    McSparin says she got the idea for the project after attending a professional development workshop this summer called the power of positivity.

    “I like the idea of letting students know they are appreciated, because we do appreciate them, I just don't think we say it enough,” she told local news outlet WDAF-TV.

    It's safe to say the challenge was effective.

    “I feel special,” said one of the boys in the video. “You should,” said his teacher. “You are special.”

    The human body is designed to move. But modern lifestyles and office jobs rarely give us the chance to move around. As we know, we're sitting while we're eating; we sit in the car and we sit while we watch TV. And many of us sit for many hours at work.

    New research shows that sitting less than three hours a day might extend your life by two years. Peter Katzmarzyk, a scientist at the University of Louisiana in the southern United States, says that sitting is ubiquitous in our lives, meaning it is something we do all the time, everywhere.

    However, Mr. Katzmarzyk says that does not mean you can sit for the rest of your waking hours. He also says you may exercise often, "We can't throw away physical activity. It's extremely important. We have 60 years of research showing us that."

    Mr. Katzmarzyk and his colleagues are part of a new generation of researchers studying how sitting all day affects length of life. "Studies that have assessed the relationship between sitting and mortality (死亡率) or television viewing and mortality are very rare. There's only been a few of them, actually five or six now, in the last four or five years." They found that cutting television time to less than two hours a day could add one point four years to life.

    Luckily, change is already coming to some offices, especially in the design of desks. A "standing desk" lets people stand while they work. Another new design is called the "treadmill desk." A treadmill is an exercise machine that lets you walk in one place. Even some U.S. schools are beginning to experiment with desks that are part bicycle to keep children moving. That's one of the strategies that many companies are using now.

    Mr. Katzmarzyk also says studying this problem has inspired his team to make a few changes in their own lives.

    Most groups of plants and animals are richer in species and more plentiful near the equator. In the ocean, that holds true for cold-blooded predators(掠食者). But warm-blooded predators are more diverse toward the poles and noticeably missing from several warm hot spots. Why?

    John Grady, an ecologist, and his team considered the possibility—warm-blooded animals need a lot to fuel their metabolism(新陈代谢). Perhaps colder waters are just richer in small fish? But they found that at higher, colder places, there isn't actually much more food around. It's more that warm-blooded animals are eating a much bigger share of it than their cold-blooded competitors.

    The real explanation is simple. An animal's speed, swiftness, and intelligence depend on its metabolism, which in turn depends on its temperature. Since birds and mammals can keep heating their bodies in icy conditions, they remain fast and attentive. By contrast, the fish they hunt become slower and duller. At some tipping point of temperature, seals, dolphins, and penguins start out swimming their prey(猎物). They become more likely to come upon targets and outpace the cold-blooded predators of their own.

    In Grady's words, "Warm-bodied predators are favoured where preys are slow, stupid and cold." That's why sharks and other predatory fish dominate near the equator, but colder waters are the kingdom of whales and seals. By keeping food to themselves in the poles, these creatures can then specialize on specific types of prey, which makes them more likely to split into separate species. The killer whales of the North Pacific, for example, include mammal-eating transients and fish-eating, year-round residents.

    But the world is changing. It's likely that the surface of the oceans will warm by 2 to 3℃ within this century. Grady's team estimates that every time the ocean's surface warms by 1℃, populations of sea mammals will fall by 12%, and populations of seals and sea lions will fall by 24%.

    But "predictions are hard," Donna Hauser from the University of Alaska Fairbanks notes. "Polar bears are losers of a warming world, but some populations are still doing well. Some groups of whales have changed the timing of their migrations; others are hunting in deeper, colder waters. These changes might make sea mammals more adaptable to changing climates. Maybe they just need to find the places where fish remain slow, stupid and cold."

Have you ever tried making art out of paper? The art of paper cutting comes from China and has a long history. The first paper cutting art was found in Sinkiang (新疆). Later,{#blank#}1{#/blank#}(这一艺术形式)spread to other parts of the world, with different regions adopting their own cultural styles.

Before the paper was invented, at that time, Chinese people used other thin materials like leaves, silk and leather to {#blank#}2{#/blank#}(刻图案)

Using scissors or a knife is {#blank#}3{#/blank#}(最常见的方式)of paper cutting. The contents involves people's daily life, architecture, and landscape and a traditional decorative Chinese paper cutting has a certain meaning behind it. In addition to the contents, Chinese paper cutting has been {#blank#}4{#/blank#}(被视作民间艺术)whose color must reflect time, location, emotion and ritual(仪式).

After knowing the art of paper cutting,you can try making one and {#blank#}5{#/blank#}(与…分享你的创作)your friend.