Researchers in China and the United States have developed a new cataract(白内障)treatment with cells that has restored vision in babies in a trial and may eventually be used in adults.

    The treatment- by doctors and staff members at the University of California, San Diego School of Medicine and Sichuan and Sun Yat-sen universities in China-was published in March 9 edition of the scientific journal Nature.

    A cataract is a clouding of the normally clear lens(晶体)of an eye. Typical cataract operation involves the removal of the cloudy lens and the insertion of an artificial one. The new operation has been tested in animals and during a small, human trial. It resulted in fewer complications(并发症)than the current harmful operation, and in regrown lenses with superior visual function in all 12 of the baby cataract patients who received the procedure.

    A congenital cataract- lens clouding that occurs at birth or shortly after- is important cause of blindness in children. In the new research, Kand Zhang, head of ophthalmic genetics at US San Diego's Shiley Eye Institute, and his colleagues relied on the regrown potential of endogenous(同源的)stem cells.

    According to Zhang, endogenous stem cells are different from other stem cells that are typically grown in a laboratory, transplanted into a patient, and can have risks of immune（免疫的）rejection, infection or cancers. Zhang told CBS News, “We invented a new operation to make a very small opening at the side of a cataractous lens bag, remove the cataract inside, allow the opening to heal, and promote potential lens stem cells to regrow an entirely new lens with vision.”

    The human trial involved 12 babies under the age of 2 who were treated with the new method, while 25 babies received thee standard operation care.. The latter group experienced a higher incidence of pos- operation danger, early- onset eye high blood pressure and increased lens clouding. The scientists reported fewer complications and faster healing among the 12 babies who has the new procedure.

    Taylor Swift was born on December 13, 1989, in Wyomissing, Pennsylvania. Swift's family ran a farm. “I had her sitting on a small horse when she was nine months old,” said Swift's mother. “If my dream had gone well, she'd be in a horse show right now.” The only obvious forerunner (先驱) of Swift's musical talent was her grandmother, an opera singer.

    That talent showed itself early: when the family went to see a Disney musical film, Swift would come out of the theater singing all the songs correctly. At the age of 11, she sang “The Star-Spangled Banner” at a Philadelphia 76ers game. The experiences during her pre-teen years encouraged the creativity to go with Swift's talent. As a child, she attended the academically competitive Wyndcroft School in Pottstown, but then switched to public schools in Wyomissing. Although it was her hometown, she didn't know any of her classmates, and she was terrified. Swift began to understand the storytelling feature of country songs, and put her feelings into songs of her own.

    One of her future hits, “The Outside”, was written when she was only 12. “I wrote that about the scariest feeling I've ever felt: going to school, looking at those faces, and not knowing who you're gonna talk to that day,” she said. “In the music, I could never feel the kind of rejection (拒绝) that I felt in middle school.” Swift's parents quickly realized that they had someone special on their hands. They sold their farm when she was 13 and moved the family to Hendersonville, Tennessee.

    Swift had the ability, above all, to put feelings into words with accuracy (准确) far beyond her years. In “Our Song” she wrote, “Our song is the slamming screen door, going out late, tapping on your window.” In the summer of 2006, “Tim McGraw” came out, and almost from the beginning the 16-year-old Taylor Swift was a star.

    In today's working world, the high school diploma program has become the initial footstep in achieving a successful career. A high school diploma is a formal document issued to certify a candidate's successful completion of a prescribed (规定的) secondary school program of studies.

    It takes four years to complete the high school diploma program. The eligibility (合格) requirements for the high school diploma vary from state to state. A high school diploma is the minimum qualification for higher education and government jobs in the United States. The opportunities for a better job are extremely limited for one who has not earned a high school diploma. To be more specific, the high school diploma can qualify one for fruitful careers in science, education, health care, the travel industry, and the legal profession.

    In some states, high school diplomas are differentiated by type such as a general diploma, an academic diploma, or a vocational diploma. A high school diploma is regarded as the minimum admission requirement for post-secondary education programs. When people apply for a green card or a US visa, a high school diploma is a valuable asset for immigrants into the United States.

    There are several ways to achieve a high school diploma. One can get the diploma through traditional classroom study. It is best suited for individuals who enjoy face-to-face interaction with their teachers and classmates. In the United States, opportunities are provided for getting high school diplomas without attending classes at school. One can earn a high school diploma at home through a combination of online and correspondence classes.

    Generally, the high school diploma programs do not have minimum age requirements. In order to get the high school diploma, the students must complete the coursework dictated by their school district. Curriculum (课程) varies from district to district. Before enrollment, a student counseling (咨询) service is recommended to most students.

    February has long been a month of romance. With the sweet smell of roses in the air, romantic films hit cinemas and love stories fill newspapers and magazines.

    On the 14th day, it is customary for a boy to take his girlfriend out to dinner, buy her flowers and chocolates, write poems, sing to her or even spell out her name with rose petals!

    This is the scene that greets you on Valentine's Day, named after Valentine who was a priest in third century Rome. When the emperor decided that single men made better soldiers than those with wives, he banned marriage.

    But Valentine continued to perform marriage ceremonies for young lovers in secret. When his actions were discovered, the emperor had him put to death.

    While in prison, it is said that Valentine fell in love with the daughter of his prison guard. Before his death, he wrote her a letter, which he signed "From your Valentine", an expression that is still in use today.

    Valentine died for what he believed in and so was made a Saint, as well as becoming one of history's most romantic figures.

    Nowadays, Valentine's Day wins the same popularity among Chinese young people. It is a time when students "don't want to be alone" according to Gao Shunjie, a student reporter for 21st Century Teens in Jinling High School, Nanjing. Some of her classmates are planning to make Valentine's cards for parents, teachers and friends. Others want to hold parties at which they will exchange small gifts and eat heart shaped cakes. The idea is to have fun and encourage people to share in the spirit of St Valentine.

    This was the first real task I received in my new school. It seemed simple: go on the Internet and find information about a man named George Washington. As I searched the name, I found that there were two famous people having the same name who looked completely different! One invented hundreds of uses for peanuts(花生), while the other led some sort of army across America. I stared at the screen, wondering which one my teacher meant. I called my grandfather for a golden piece of advice; let the coin decide. I flipped(掷) a coin and Ah! Tails (背面)! My report would be about the great man who invented peanut butter, George Washington Carver.

    Weeks later, I stood in front of the classroom and proudly read my homework. But things started to get strange. I looked around the room, only to find my classmates with big smiles on their faces and tears in their eyes and my stone-faced teacher. I was completely lost. "What could be causing everyone to act this way?"

    Oh well, I dropped the paper and sat down at my desk, burning to find out what I had done wrong. As a classmate began his report, it all became clear, "My report is on George Washington, the man who started the American War of Independence." The whole world became quiet! How could I know that my teacher meant that George Washington?

    Of course, my subject result was awful. Sad but fearless, I decided to turn this around. I talked to the headmaster Miss Lancelot, but she said firmly: No re-dos; no new score. I felt that it was not fair, and I believed I deserved a second chance. So I threw myself heartily into my work for the rest of the school year. Ten months later, I sat in the headmaster's office again, but this time a completely different conversation. I smiled and flashed back to the terrible moment at the beginning of the year as the headmaster told me I was good enough to skip(跳过) the 6th grade and started the 7th grade next term.

    The school year has barely started in Denver, and French teacher Tiffany Choi is already worried that her students are suffering from absent-mindedness. The problem isn't texting, playing video games or passing notes. It's Denver's ongoing heat wave.

    "Today was a little bit hot, so I noticed kids were very sleepy and they were having to get up to drink water quite often." said Choi, who works at Denver's East High School. "If you lose too much water, and you have to keep going to the water fountain, that can take away from their classroom experience." While nodding off in class on a warm day may seem like a right of passage for the average teen, Choi's observation carries a bigger consequence than parched (干燥的) lips.

    "There's been quite a few media reports about teachers noticing that students weren't able to focus on hotter days," said R Jisung Park, a researcher, "Does a hotter climate during the school year actually affect the rate of learning?" The drops in academic achievement couldn't be explained by hotter weekends or hotter summers, but the trend was connected to higher temperatures on school days alone.

    The connection between lost learning and a greater number of hot days is one more example of how climate change is already affecting our lives-and it's an alarm bell for what we stand to lose in the future. Humans still have time to lessen the worst consequences of continued global warming. But unless significant changes occur in the next decade-which seem more and more unlikely—the world will be locked into an inescapable period of heat waves unlike our species has ever seen.