Mark Twain has been called the inventor of the American novel.And he surely deserves additional praise：the man who popularized the clever literary attack on racism.

     I say clever because anti­slavery fiction had been the important part of the literature in the years before the Civil War.H.B.Stowe's Uncle Tom's Cabin is only the most famous example.These early stories dealt directly with slavery.With minor exceptions，Twain planted his attacks on slavery and prejudice into tales that were on the surface about something else entirely.He drew his readers into the argument by drawing them into the story.

     Again and again，in the postwar years，Twain seemed forced to deal with the challenge of race.Consider the most controversial，at least today，of Twain's novels，Adventures of Huckleberry Finn.Only a few books have been kicked off the shelves as often as Huckleberry Finn，Twain's most widely read tale.Once upon a time，people hated the book because it struck them as rude.Twain himself wrote that those who banned the book considered the novel “trash and suitable only for the slums(贫民窟)．”More recently the book has been attacked because of the character Jim，the escaped slave，and many occurences of the word nigger.(The term Nigger Jim，for which the novel is often severely criticized，never appears in it.)

     But the attacks were and are silly—and miss the point.The novel is strongly anti­slavery.Jim's search through the slave states for the family from whom he has been forcibly parted is heroic.As J．Chadwick has pointed out，the character of Jim was a first in American fiction—a recognition that the slave had two personalities，“the voice of survival within a white slave culture and the voice of the individual：Jim，the father and the man.”

There is much more.Twain's mystery novel Pudd'nhead Wilson stood as a challenge to the racial beliefs of even many of the liberals of his day.Written at a time when the accepted wisdom held Negroes to be inferior(低等的)to whites，especially in intelligence，Twain's tale centered in part around two babies switched at birth.A slave gave birth to her master's baby and，for fear that the child should be sold South，switched him for the master's baby by his wife.The slave's lightskinned child was taken to be white and grew up with both the attitudes and the education of the slave­holding class.The master's wife's baby was taken for black and grew up with the attitudes and intonations of the slave.

     The point was difficult to miss：nurture(养育)，not nature，was the key to social status.The features of the black man that provided the stuff of prejudice—manner of speech，for example—were，to Twain，indicative of nothing other than the conditioning that slavery forced on its victims.

Twain's racial tone was not perfect.One is left uneasy，for example，by the lengthy passage in his autobiography(自传)about how much he loved what were called“nigger shows”in his youth—mostly with white men performing in black­face—and his delight in getting his mother to laugh at them.Yet there is no reason to think Twain saw the shows as representing reality.His frequent attacks on slavery and prejudice suggest his keen awareness that they did not.

     Was Twain a racist？Asking the question in the 21st century is as wise as asking the same of Lincoln.If we read the words and attitudes of the past through the“wisdom”of the considered moral judgments of the present，we will find nothing but error.Lincoln，who believed the black man the inferior of the white，fought and won a war to free him.And Twain，raised in a slave state，briefly a soldier，and inventor of Jim，may have done more to anger the nation over racial injustice and awaken its collective conscience than any other novelist in the past century.

    Deborah Cohen is a senior natural scientist at the Rand Corp and the author of the book A Big Fat Crisis: The Hidden Forces Behind the Obesity Epidemic and How We Can End It. According to the book, there are lots of misunderstandings of obesity.

1).If you're obese, blame your genes.

    Obesity rates have increased. Yet, between 1980 and 2000, the number of Americans who are obese has doubled—too quickly for genetic factors to be responsible.

    At restaurants, a dollar puts more calories on our plates than ever before, because restaurant meals usually have more calories than what we prepare at home, so people who eat out more frequently have higher rates of obesity than those who eat out less.

2).If you're obese, you lack self-control.

    Research shows that if we are faced with too much information, we have a tendency to make poor dietary choices. Our world has become so rich in temptation that we can be led to consume too much in ways we can't understand. Even the most vigilant (警觉的) people may not be up to the task of controlling themselves.

3).Lack of access to fresh fruits and vegetables is responsible for obesity.

    Although the US Department of Agriculture estimates that fewer than 5 percent of Americans live in the “food deserts”, about 65 percent of the nation's population is overweight or obese. For most of us, obesity is not related to access to more fresh fruits and vegetables, but to the choices we make in supermarkets.

4).The problem is not that we eat too much, but that we don't exercise.

    Michelle Obama's “Let's Move” campaign is based on the idea that if kids exercise more, childhood obesity rates will decrease. But there was no significant decrease in physical activity levels as obesity rates climbed in the 1980s and 1990s. In fact, although a drop in work-related physical activity may account for up to 100 fewer calories burned, leisure physical activity appears to have increased. The problem is that we eat too much.

    Why Do People Blink Their Eyes?

    People blink(眨眼) their eyes tens of thousands of times every day. Scientists have long believed blinking was an involuntary movement and served mainly to keep the eyeballs wet. But a new study suggests it has a more important purpose.

    An international team of scientists from the University of California at Berkeley studied the blinking of human eyelids. The journal Current Biology published their findings. The team said they found that blinking “repositions our eyeballs so we can stay focused” on what we are seeing. They said that when we blink our eyelids, the eyes roll back into their sockets--the bony area that surrounds and protects the eyes. However, the researchers found the eyes don't always return to the same position. They said this causes the brain to tell the eye muscles to reorganize our eyesight.

    Gerrit Maus is the lead writer of the report. He serves as an assistant professor of psychology at Nanyang Technological University in Singapore. Maus says: “Our eye muscles are quite sluggish(迟缓的) and imprecise, so the brain needs to constantly adapt its motor signals to make sure our eyes are pointing where they're supposed to. Our findings suggested that the brain measures the difference in what we see before and after a blink, and commands the eye muscles to make the needed corrections.” The researchers said that without such corrections our surroundings would appear unclear and even jumpy. They said the movement acts “like a Steadicam(摄影稳定器) of the mind.”

    The researchers said they asked volunteers to sit in a dark room while staring at a small dot on a flat surface. They used special cameras to follow the volunteer's blinks and eye movements. After each blink, the dot was moved one centimeter to the right. The volunteers did not notice this, but the brain did. It followed the movement and directed the eye muscles to refocus on the dot. After the dot was moved in this way 30 times, the volunteers' eyes changed their focus to the place where they predicted it would be.

    Professor Maus says “Even though participants did not consciously register that the dot had moved, their brains did, and adjusted with the corrective eye movement. These findings add to our understanding of how the brain constantly adapts to changes, commanding our eye muscles to correct for errors in our bodies' own hardware.”

    It is natural that young people are often uncomfortable when they are with their parents. They say that their parents don't understand them. They often think that their parents are out of touch with modern ways, that they are too serious and too strict with their children, and that they seldom give their children a free hand.

    It is true that parents often find it difficult to win their children's trust and they tend(倾向) to forget how they themselves felt when young.

    For example, young people like to act on the spot without much thinking. It is one of their ways to show that they have grown up and they can face any difficult situation. Old people worry more easily. Most of them plan things in advance, at least in the back of their minds, and do not like their plans to be upset by something unexpected.

    When you want your parents to let you do something, you will have better success if you ask before you really start doing it.

    Young people often make their parents angry with their choices in clothes, in entertainment and in music. But they do not mean to cause any trouble; it is just that they feel cut off from the older people's world, into which they have not yet been accepted. That's why young people want to make a new culture of their own, and if their parents don't like their music or entertainment or clothes or their way of speech, this will make the young people extremely happy.

    Sometimes you are so proud of yourself that you do not want your parents to say “yes” to what you do. All you want is to be left alone and do what you like. It is natural enough, after being a child for so many years, when you were completely under your parents' control.

    If you prefer to control your life, you'd better win your parents over and try to get them to understand you. If your parents see that you have a high sense of responsibility, they will certainly give you the right to do what you want to do.

The history of Australian Rules Football

    Australian Rules Football is called by many nicknames. Lovers of the game just call it "football" or "footy." When contrasted with other forms of football, it is called "Aussie Rules" or "AFL". AFL stands for Australian Football League, which is the most prestigious league in Australia.

    Australia Rules Football was created by Tom Wills in 1858. He wanted to create a sport that would keep cricket players fit through the winter. He began by writing a letter that explained his purpose to a sports magazine. It also called for the creation of a football club. In 1858, Wills and others played an experimental match that was the first game of Australian football. But few details about this match have survived.

    On August 7, 1858, two important events for the game occurred. The Melbourne Football Club was founded. It was one of the world's first football clubs in any code. Also, a famous match between Melbourne Grammar School and Scotch College was played. It was umpired(仲裁)by Tom Wills. A second day of play took place on August 21, and then there was a third and final day on September4. The two schools have competed every year since.

    The game is played between two teams of 18 players on an oval that can also be used for cricket. These playing fields can be up to 185m long. This is almost four times the size of fields used in other forms of football.

    A point called "a behind" is scored when the ball goes across the line and between a goal post and a behind post. A behind point is also scored if the ball is touched by any body part of either team's member as it passes between the goal posts. A goal is worth six points, and a behind is worth one point.

    Are you afraid of sharks? What about snakes or spiders? Put those fears aside: because in the U.S. you're far more likely to be killed or injured by a deer skipping across the road.

    Deer cause more than 200 humans deaths each year, plus some 29, 000 injuries, all because of 1.2 million collisions between vehicles and deer. Most incidents occur in the eastern U.S., where deer prosper without natural predators like wolves and mountain lions.

    "That's the region in the U.S. where deer-vehicle collisions are such a problem, and where it seems like an effective large carnivore reintroduction could make a really big difference." says wildlife biologist Laura Prugh from University of Washington. She thinks it would help to reintroduce predators like mountain lions, also known as cougars, pumas or panthers, to parts of their historic range from which they've been driven out.

    The researchers say that bringing the predators back to the eastern U.S. would mean 22 percent fewer collisions between cars and deer over three decades. Each year would see five fewer human deaths, 680 fewer injuries and a savings of some 550 million. Sophie L. Gilbert thinks there are great socioeconomic benefits of large predator restoration through reduced wildlife-vehicle collisions and she says, says, "Cougars have shown that they can coexist in short distance with people, with very few conflicts, in a lot of areas out west."

    Still, some folks might be understandably nervous about this kind of plan. After all, reintroducing predators doesn't come without risks to pets and to livestock, and very occasionally to people.

    "Our fear of large predators is so natural and intense that I don't think it's possible to just completely clear it with statistics… What I hope is that knowing that there actually can be some measurable benefits might make people a little more supportive and maybe balance that fear a little bit." says Laura.

    Indeed, the statistics show that cougars would prevent five times as many human deaths from deer-related accidents as they would cause by attacks. But it'll be a tough sell: the press will cover cougar attacks, but a statistically prevented death does not make the news. Nevertheless, "If people in the west can put up with having mountain lions around, I would hope that New Yorkers would be up for the challenge as well."