When Kate's paintings were on show in London，a poet described her paintings as “a ribbon (丝带）around a bomb”．Such comments seem to suggest Kate had a big influence on the art world of her time．Sadly，she is actually a much bigger name today than she was during her time．

    Born in 1907 in a village near Mexico City，Kate suffered from polio（小儿麻痹症）at the age of seven．Her spine (脊柱)became bent as she grew older．Then，in 1925，her back was broken in several places in a school-bus accident．Throughout the rest of her life，the artist had many operations，but nothing was able to cure the terrible pain in her back．However，the accident had an unexpected side effect．While lying in her bed recovering，Kate taught herself to paint．

    In 1929，she got married to Diego Rivera，another famous Mexican artist．Rivera's strong influences on Kate's style can be seen in her early works，but her later works from the 1940s，known today as her best works，show less influence from her husband．

    Unfortunately，her works did not attract much attention in the 1930s and1940s，even in her home country．Her first one-woman show in Mexico was not held until 1953．For more than a decade after her death in 1954，Kate's works remained largely unnoticed by the world，but in the 1970s her works began to gain international fame at last．

    Today Dante had a small skating competition in his class. Before we went to the competition, I asked him if he wanted to wear something nice for the competition and he said, “Who cares? It's not important.” When we showed up at the rink(溜冰场), we found that most of the kids were dressed up. One boy who was around nine years old was my son's friend, wearing a dress shirt and a pink vest. I walked over to his mother saying how beautifully dressed he was. But his mother said, “He didn't want to dress up. He said that this competition was not important for him to dress up.”

    I thought it was interesting that neither Dante nor his friend viewed the competition as important and neither wanted to dress up. I started to wonder if this was how a child learned what was “important” and what wasn't.

Interestingly, this boy won two medals and Dante won none.

    Parents and teachers often instill (灌输) what they think is important: then children will accept the opinions of the adults. Gradually, they grow up stressing about how they look, how many medals they get, what color the medals are, how good their grades are, what a great “job” they can get in life, what a big house they can live in... etc.

    Dante taught me an important lesson today. He taught me what was unimportant. Life goes on long after the medal ceremony whether you win a medal or not.

    Although English is not as old as Chinese, it is spoken by many people around the world every day. English speakers are always creating (创造) new words, and we are often able to know where most words come from.

    Sometimes no one may really know where a word comes from. Did you ever think about why hamburgers are called hamburgers, especially when they are not made with ham? About a hundred years ago, some men went to America from Europe. They came from a big city in Germany called Hamburg. They didn't speak good English, but they ate good food. When some Americans saw them eating a round piece of beef, they asked the Germans what is was. The Germans didn't understand the question and answered, “We come from Hamburg.” One of these Americans owned a restaurant. He had an idea. He cooked some round pieces of bread and started selling them. Such bread came to be called “hamburgers”. Today, “hamburgers” are sold in many countries around the world.

    Whether this story is true or not, it certainly is interesting. Knowing why any word has a certain meaning is interesting, too. This reason, for most English words, can be found in any large English dictionary.

    Every summer, the Serengeti plains (平原) of Africa are worth visiting. Millions of wild animals begin their 1,800-mile journey northwards on their annual migratory (迁移的) route.

    In the month of November, polar bears in their thousands cross the Canadian Arctic, as they head towards the ice sheets of Hudson Bay. The sea ice that forms every winter is the key to the bear's managing to exist, for here they hunt for seals (海豹).

    The Great Bustard, one of the heaviest flying birds, migrates each year across Europe and Asia to its wintering grounds. Unluckily, these and other migratory animals are in danger from human activity.

    We have written several articles on climate change and the effect of rising ocean temperatures. Since 1979, ice sheets in the Arctic have gone down by 30 percent. What does this mean for polar bears? They are forced to stay on land for longer periods of time, which delays their search for food. As a result, bears today are 60 pounds lighter than what they were. Besides, smaller bears also produce weaker babies, and their chances of survival are at risk. In the plains of Africa, migratory animals like gazelles are traveling long distances for food, just to avoid falling prey (牺牲品) to humans who hunt them.

    In an unusual step, experts from 120 countries have agreed to protect 31 migratory mammals, fish and birds. The United Nation's 11th annual Conservation of Migratory Species of Wild Animals (CMS) was held in Quito, Ecuador. For the first time, 900 experts attended the conference, and the enthusiastic support shows the world is united in conservation (保护) efforts.

    What does getting on a protected list mean? Countries that have signed the agreement will be required to pass laws locally and work with other countries that fall within the animal's migratory path. Only one animal did not make the list. The African lion was rejected (拒绝) for lack of information of the countries where it lives.

    Exactly five years ago, on New Year's Eve, I was invited to a children's ball by a man high up in the business world, who had his connections, his circle of acquaintances, and his close friends. So it seemed as though the children's ball was merely an excuse for the parents to come together and discuss matters of interest to themselves, quite innocently and casually.

    I was an outsider, and, as I had no special matters to air, I was able to spend the evening independently of the others. There was another gentleman present who like me had just stumbled upon (偶然发现) this affair of domestic happiness. He was the first to attract my attention. His appearance was not that of a man of noble birth. He was tall, rather thin, very serious, and well dressed. Obviously he had no heart for the family celebration. The instant he went off into a corner by himself the smile disappeared from his face, and his thick dark brows knitted into a frown(皱眉). He knew no one except the host and showed every sign of being bored to death, though bravely keeping the role of thorough enjoyment to the end. Later I learned that he was a provincial, had come to the capital on some important business, had brought a letter of recommendation to our host, and our host had taken him under his protection, not at all with love. It was merely out of politeness that he had invited him to the children's ball.

    They did not play cards with him. They did not offer him cigars. No one entered into conversation with him. Possibly they recognized the bird by its feathers from a distance. Thus, my gentleman, not knowing what to do with his hands, was compelled(迫使) to spend the evening stroking (抚摸) his whiskers(胡须). His whiskers were really fine, but he stroked them so eagerly that one got the feeling that the whiskers had come into the world first and afterwards the man in order to stroke them.

    Rivers are earthly arteries(要道) for the nutrients, deposits and freshwater that sustain healthy, diverse ecosystems. Their influence extends in multiple dimensions—not only along their length but below­ground to aquifers(蓄水层) and periodically into nearby floodplains.

    They also provide vital services for people by fertilizing agricultural land and feeding key fisheries and by acting as transportation corridors. But in efforts to ease ship passage, protect communities from flooding, and draw off water for drinking and irrigation, humans have increasingly constrained and broken these crucial water ways. “We try to control rivers as much as possible,” says Gunther Grill, a hydrologist at McGill University.

    In new research published in May in Nature, Grill and his colleagues analyzed the barriers to 12 million total kilometers of rivers around the world. The team developed an index(指数) that evaluates six aspects of connectivity—from physical fragmentation (by dams, for example) to flow regulation (by dams or levees) to water consumption—along a river's various dimension. Rivers whose indexes meet a certain threshold(临界值) for being largely able to follow their natural patterns were considered free­flowing.

    The researchers found that among rivers longer than 1,000 kilometers (which tend to be some of those most important to human activities), only 37 percent are not blocked along their entire lengths. Most of them are in areas with a minimal human presence, including the Amazon and Congo basins and the Arctic. On the contrary, most rivers shorter than 100 kilometers appeared to flow freely—but the data on them are less comprehensive, and some barriers might have been missed. Only 23 percent of the subset of the longest rivers that connect to the ocean are uninterrupted. For the rest, human infrastructure is starving estuaries(河口) and deltas (such as the Mississippi Delta) of key nutrients. The world's estimated 2.8 million dams are the main cause, controlling water flow and trapping deposits.

    The new research could be used to better understand how proposed dams, levees and other such projects might impact river connectivity, as well as where to remove these fixtures to best restore natural flow. It could also help inform our approach to rivers as the climate changes, says Anne Jefferson, a hydrologist at Kent State University, who was not involved in the work. Existing infrastructure, she says, “has essentially been built to a past climate that we are not in anymore and are increasingly moving away from.”