The arm bones of women who lived 7-000 years ago show a surprising level of strength-even higher than today's professional athletes. That's according to a first-ever study comparing prehistoric(史前的)bones to those of living people. The finding suggests a revision of history — the everyday lives of prehistoric women were filled with hard labor, rather than just sitting at home doing lighter tasks while the men struggled and fought for life.

    “Before the study, there are no clear records describing how our ancient ancestors lived. It can be easy to forget that bone is a living tissue, one that responds to the difficulties we put our bodies through,” said lead author Alison Macintosh. “Physical force and muscle activity both put pressure on the bone. The bone reacts by changing in shape, thickness and other aspects over time. ”

    Previous studies only compared female bones to contemporary male bones, the researchers said — and that's a problem, because the response of male bones to stress and change is much bigger than that of women. For instance, as humans moved from a hunter-gatherer lifestyle constantly on the move to a more settled agrarian (农耕的)one, changes can be observed in the structure of the shinbone (胫骨) — and these changes were much more evident in men.

    However, a comparison of the bones of prehistoric women to the bonos of living female athletes can help us work out a more accurate picture of what those prehistoric women were doing. “By analyzing the bones of living people and comparing them to the ancient hones, we can start to explain the kinds of labor our ancestors were performing,” Macintosh said. What they found was that women's leg strength hasn't changed a great deal, but their arms used to be very powerful. Prehistoric women, the researchers found, had arm strength 11〜16 percent stronger than those of modern rowers, and 30 percent stronger than those of non-athletes.

    The quality of our seafood has been in the news a lot lately. A new study has found that people who eat seafood are also eating plastic — 11,000 pieces of microplastic per year to be exact.

    Researchers at the University of Ghent in Belgium found that seafood eaters are consuming plastic at a concerning rate.

    “Per serving of mussels (贻贝), which contains about 300 grams of mussel meat, you get 300 pieces of plastic inside your body,” researchers wrote. Researchers don't yet know the implications of eating microplastic, but they worry that it could have negative consequences on our health.

    While we don't know what microplastic does yet to humans, we do know what it does to sea animals. In earlier studies, scientists have found that when fish eat microplastics, it prevents their growth and changes their feeding patterns. In fact, fish will stop eating natural sources of nutrients, and only go for plastic.

    When you're done using plastic, a small portion (部分) may be recycled. However, more than likely it's in a landfill or making its way towards the ocean. Once rubbish hits the water, sea creatures may mistake it for food. This often leads to poisoning or death. If they get caught for human's food, the plastic may very well make its way back to you — on your dinner plate.

    According to a study published in Science magazine, eight million tons of plastic go into our waterways every year. The problem is so serious that scientists say that by 2050 the weight of plastic in our oceans will outweigh fish. And just because it's out of sight, it doesn't mean it should be out of mind.

    There's no immediate way to prevent microplastic from ending up in your body. However, you can help reduce the amount of plastic reaching rivers, lakes and oceans in the first place. You can make a difference with your choices every day. Even small changes will add up. While your dinner may contain microplastic, you can help prevent the future generations from having that same problem.

    For a long time being happy was considered natural, and there was nothing special to do about it. Now we know that we can work at getting along well with other people. It is possible to act in such a way that other people will like us better.

    One way is being unselfish, not wanting everything your own way or asking for the best share of everything, including the attention of your friends. Another way is to look for good points, not bad ones in other people.

    You don't have to be spineless(无骨气的)in order to be popular. In fact, you will be liked and respected(尊重)if you are not afraid to stand up for your rights(权利). But do it politely and pleasantly. One way to develop a good character is being friendly and polite to your own group, to older people, to strangers and especially to those who do not look important or do not interest you.

    You cannot expect to be perfect, so you must learn not to be too unhappy when you make a mistake. Everyone makes mistakes, and no one is to be blamed unless he refuses to learn from them. Many young people become discouraged(泄气的) when they know their unpleasant qualities—selfishness, laziness, etc. Just remember that we all have some of these faults and have to fight against them.

    When something is wrong, it is best to try to make it right. Perhaps you don't like a teacher or a classmate. Try to see why, and look at yourself, too. Make sure that you are not doing something to make others dislike you. In time, things may turn out all right, then you simply have to learn to get along the best you can with the situation, without thinking too much about it. Worrying never helps in a situation you can't change.

    Finding a mountain goat resting high on a cliff(悬崖) might thrill many of the millions of tourists who visit Wyoming's Grand Teton National Park every year, but park officials say it might be time for the bearded animals to go.

    The problem, according to the park, is that Grand Teton's 100 or so mountain goats threaten about 80 bighorn sheep. The bighorn sheep numbered as many as 125 just a few years ago. The strong goats spread disease and compete with bighorn sheep for food. Unlike small-sized bighorn sheep, Grand Teton's mountain goats aren't native to the park. They were introduced to the park in the 1960s.

    Grand Teton spokeswoman Denise Germann said, “We've got a management responsibility to protect the native species. After hearing from the public on the proposal (建议) in January, park officials expect to decide as soon as mid-February on what to do about the mountain goats.”

    The goats are reproducing rapidly. Now might be the best time to reduce the animals before they're too many to bring under control, according to the Park Service.

    One wildlife biologist who studies bighorn sheep praised the proposal. Mountain goats' original habitat is nowhere close to where they've been introduced in the U.S. to provide hunting opportunities, said Rob Roy Ramey II, with Nederland, Colorado-based Wildlife Science International, Inc.

    Wildlife managers should get rid of mountain goats not only in Grand Teton but elsewhere to help struggling bighorn sheep, Ramey said. “Unfortunately, state wildlife agencies sell nonnative wildlife viewing opportunities to the public,” Ramey said. “This is not a zoo in the wilderness. It should really be for native wildlife.”

    This year marks the 170th anniversary of Paul Gauguin's birth. He lived for just 54 years but he packed his brief life with activity.

    The French painter spent his early childhood in Peru before returning to France. As an adult, he continued to travel a lot. Most famously, he spent much of the last decade of his life in Tahiti, an island in southern Pacific Ocean. Indeed, Gauguin is best known for his colorful paintings of Tahitians and their culture.

    The restlessness of this great painter has been normal among modern artists since the middle of the 19th century. They're never satisfied for long with a certain style or way of life. Once something becomes conventional, it's turned down.

    The artistic culture that Gauguin developed from was that of Impressionism (印象派). Painters like Claude Monet had wanted to paint how they saw the world, not how their teachers taught them it should be seen. Gauguin, and similar artists like his friend Vincent van Gogh, moved even further away from "respectable" art than the Impressionists. For them, it was not simply a matter of seeing the world differently, but feeling and thinking about it differently, too.

    Gauguin saw, felt and thought differently from most members of European society. He thought that European culture was too fancy and not spontaneous. This is why he turned to the traditions of other parts of the world, like Africa, and, eventually, Tahiti. Artists like Gauguin used the word "primitive" for these cultures, but not as a negative term. For him, Europe, in becoming modem, industrial and scientific, seemed less natural than other parts of the world.

    In truth, Gauguin's paintings may be unconventional but they are certainly not "primitive". They are the work of a painter with great awareness of what he was doing. It was this awareness that made him such an important painter for those that came after, in the 20th century. When we look closely at the works of Gauguin we begin to understand Pablo Picasso, and especially Henri Matisse, a little better.

We use both words and body language to express our thoughts and opinions in our interactions with other people. We can learn a lot about what people are thinking by watching their body language. Words are important, but the way people stand, hold their arms, and move their hands can also give us information about their feelings.

Just like spoken language, body language varies from culture to culture. The crucial thing is using body language in a way that is appropriate to the culture you are in. For example, making eye contact—looking into someone's eyes—in some countries is a way to display interest. In other countries, by contrast, eye contact is not always approved of. For example, in many Middle Eastern countries, men and women are not socially permitted to make eye contact. In Japan, it may demonstrate respect to look down when talking to an older person.

The gesture for "OK" has different meanings in different cultures. In Japan, someone who witnesses another person employing the gesture might think it means money. In France, a person encountering an identical gesture may interpret it as meaning zero. However, you should avoid making this gesture in Brazil and Germany, as it is not considered polite.

Even the gestures we use for "yes" and "no" differ around the world. In many countries, shaking one's head means "no", and nodding means "yes". By comparison, in Bulgaria and southern Albania, the gestures have the opposite meaning. There are also differences in how we touch each other, how close we stand to someone we are talking to, and how we act when we meet or part. In countries like France and Russia, people may kiss their friends on the cheek when they meet. Elsewhere, people favour shaking hands, bowing from the waist, or nodding the head when they meet someone else.

Some gestures seem to have the same meaning everywhere. Placing your hands together and resting them on the side of your head while closing your eyes means "sleep". A good way of saying "I am full" is moving your hand in circles over your stomach after a meal.

Some body language has many different uses. Perhaps the best example is smiling. A smile can help us get through difficult situations and find friends in a world of strangers. A    smile    can    break    down    barriers. We can use a smile to apologise, to greet someone, to ask for help, or to start a conversation. Experts suggest smiling at yourself in the mirror to make yourself feel happier and stronger. And if we are feeling down or lonely, there is nothing better than seeing the smiling face of a good friend.