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.

It's true to say that technology makes our lives easier. However, increasingly scientists are saying that we need to give ourselves a break—--otherwise we put ourselves at risk(风险) of developing hundreds of health problems. Over the summer the days are longer and sunnier. Why not put this free time to good use and do something away from technology?

    You could learn a new skill. There are hundreds of possibilities: cooking, a musical instrument or a new sport. Haven't you always wanted to learn how to knit(编织)? You could use your free time to practice these new things, which might lead to an exciting opportunity in the future.

    If you just want to relax, why not head to a beach? Take along your favorite book and relax on the sand, or go for a walk along the coastline. If you don't live near a beach, you could go to your local park. Why not have a picnic, or try to explore some of the local wildlife? You could even get involved in the latest craze(狂热): adult coloring books! Coloring is a surprising thing to help you relax, and it can be a nice way to escape from the stress of modern life!

    Whatever you choose to do, try something new! You might surprise yourself and find a hidden gift within you; you might make new friends along the way. Next time you find yourself changing TV channels(频道) from one to another without a clear purpose, think about what else you could spend your time doing.

    The Coolest Inventions

    An Oceans Vacuum(吸尘器)

    There's a collection of plastic trash in the middle of the Pacific Ocean. It's bigger than Texas and growing. The way to clean it up now is to catch it with nets. That is both costly and slow. Instead, the Ocean Cleanup Project proposes a 62-mile-long floating barrier that would use natural currents to trap trash. If next year's trials succeed, a full cleanup operation would aim to start in 2020. It could reduce the trash by 42% over 10 years.

    Easy-On Shoes

    In 2012, Matthew Walzer, a high school student with a disability, sent a note to Nike. “My dream is to go to college,” he wrote, “without having to worry about someone coming to tie my shoes every day.” Nike assigned a design team to the challenge. This year, they came out with their solution: the FlyEase. The basketball shoe can be fastened with one hand. A pair of Nike FlyEase shoes sells for $130.

    An Airport for Drones (无人机)

    As Amazon, Google, and others get ready for drone delivery service, there is one big question: What kinds of home bases will their drones have? Rwanda, in Africa, may have the answer. There, workers will soon start work on three “drone ports”. The goals is to make it easier to transport food, medical supplies, electronics, and other goods through the hilly countryside. Construction is set to be completed in 2020.

    Some houses are designed to be smart. Others have smart designs. An example of the second type of house won an Award of Excellence from the American Institute of Architects.

    Located on the shore of Sullivan's Island off the coast of South Carolina, the award-winning cube-shaped beach house was built to replace one smashed to pieces by Hurricane（飓风）Hugo 10 years ago. Before Hugo, many new houses built along South Carolina's shoreline were poorly constructed, and enforcement of building rules wasn't strict, according to architect Ray Huff, who created the cleverly-designed beach house. Soon after Hugo, all new shoreline houses are required to meet stricter, better-enforced rules. The new beach house on Sullivan's Island should be able to withstand a Level 3 hurricane with peak winds of 179 to 209 kilometers per hour.

    At first sight, the house on Sullivan's Island looks anything but hurricane-proof. Its redwood shell makes it resemble “a large party lantern (灯笼)” at night, according to one observer. But looks can be misleading. The house's wooden frame is reinforced with long steel rods to give it extra strength.

    To further protect the house from hurricane damage. Huff raised it 2.7 meters off the ground on timber pilings－long, slim wood pieces anchored deep in the sand. Pilings might appear insecure, but they are strong enough to support the weight of the house. They also raise the house above storm waves. The pilings allow the waves to run under the house instead of running into it. 'These waves come ashore at terrible speeds and cause most of the damage done to beach-front buildings,” said Huff.

    Huff designed the timber pilings to be partially hidden by the house's ground-to-roof shell. “The shell masks the pilings so that the house doesn't look like it's standing with its pant legs (裤腿) pulled up,” said Huff. In the event of a storm, the shell should break apart and let the waves rush under the house, the architect explained.

    The Marches were a happy family, Poverty, hard work, and even the fact that Father March was away with the Union armies could not down the spirits of Meg, Jo, Beth, Amy, and Marmee, as the March girls called their mother.

    The March sisters tried to be good but had their share of faults. Pretty Meg was often displeased with the schoolchildren she taught; boyish Jo was easy to become angry; golden-haired schoolgirl Amy liked to show up; but Beth, who kept the house, was loving and gentle always.

    The happy days passed and darkness came when a telegram arrived for Mrs. March. “Your husband is very ill,” it said, “come at once.” The girl tried to be brave when their mother left for the front. They waited and prayed. Little Beth got scarlet fever (猩红热) when she was taking care of the sick neighbor. She became very ill but began to recover by the time Marmee was back. When Father came home from the front and at that joyful Christmas dinner they were once more all together.

    Three years later the March girls had grown into young womanhood. Meg became Mrs. Brooke, and after a few family troubles got used to her new state happily. Jo had found pleasure in her literary efforts. Amy had grown into a young lady with a talent for design and an even greater one for society. But Beth had never fully regained her health, and her family watched her with love and anxiety.

    Amy was asked to go and stay in Europe with a relative of the Marches'. Jo went to New York and became successful in her writing and had the satisfaction of seeing her work published there. But at home the bitterest blow was yet to fall Beth had known for some time that she couldn't live much longer to be with the family and in the spring time she died.

    News came from Europe that Amy and Laurie, the grandson of a wealthy neighbor, had planned to be married soon. Now Jo became ever more successful in her writing and got married to Professor Bhaer and soon afterwards founded a school for boys.

    And so the little women had grown up and lived happily with their children, enjoying the harvest of love and goodness that they had devoted all their lives to.

    They are called "sea parrots", and sometimes "clowns (小丑) of the sea"!

    Atlantic puffins (海鹦) are small seabirds which are around 25 cm in length. They have black and white feathers and a large parrot-like beak (鸟喙). The beak changes color during the year. In winter, the beak has a dull gray color, but it turns orange in spring!

    Puffins spend most of their lives out at sea, resting on the waves when not swimming. They live on the eastern coast of Canada and the United States, and the western coast of Europe.

    Puffins live off small fish such as herring, hake and sand eels. Puffins flap (拍) their wings up to 400 times a minute and speeding through the air at up to 88 km an hour. Wow! What's more, puffins can dive down 60m under water in search of their favorite fish.

    In spring and summer, thousands of puffins stay together on the coasts and islands of the North Atlantic Ocean to start a puffin family. They usually pair up with the same partner as before some may have been together for 20 years! Puffins dig out a hole usually in a grassy bank. Both parents take it in turn to incubate (孵化) the egg for the next 36-45 days!

Although puffins are not classed as an endangered animal, their population in some places is becoming smaller. The main reasons are overfishing, which can lead to a shortage of food for puffins, and pollution—especially oil spills (溢出). Not only does the oil make these beautiful birds sick, it harms their feathers.