Over the last week, a "poisonous kale（甘蓝菜）" theory has been going widespread after an article warned that the vegetable was associated with a variety of medical conditions. It's time to separate fear from fact on the health benefits of kale.

    As a member of the cabbage family, kale is low in calories and rich in nutrients and minerals, especially vitamin A,C and K. Consumed for thousands of years, it's been a health plus for millions of eaters throughout the world.

    However, numerous web articles have reported on some evidence offered by a medicine researcher. The researcher found that thallium（铊）was detected in a few people who were heavy consumers of kale. Thallium is a heavy metal often found in trace amounts（微量）in soil and minerals. His conclusion was that these medical conditions were connected to the impact that trace amounts of thallium detected in some kale samples had on the body.

    I don't think the conclusion is based on a strict scientific basis. It's essential to point out that the original report was in a web magazine, not a scientific journal which is subject to peer review by other scientists. A scientific review includes a careful evaluation of how the findings and conclusions were made. Certain factors are critical before an evidence-based conclusion can be made, such as: how many people were in a study; how well controlled were other factors; how much kale was consumed and for how long; how much thallium was in the kale.

    It is a fact that kale and other vegetables can absorb thallium from the soil. But the ability for a plant to absorb traces of a chemical does not automatically make it harmful to your health. And even finding measurable amounts of thallium in someone's body doesn't imply that the thallium is causing an ill health effect, according to the CDC.

    But we can still learn a lesson from this. Plants grow in soil. Growers must continue to be careful in monitoring the quality of their soil. And what about consumers? Eat your kale—and include lots of other colorful fruits and vegetables. As with all things in nature, variety is key for good health.

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    When introducing American universities, some of the first institutions（机构）to mention are the Ivy League schools. Originally, the Ivy League was an athletic conference made up of 8 private institutes of higher learning in northeastern United States. However, as time went on, these schools also became known for their excellence in academics besides athletics. Included in the Ivy League schools are Brown University, Columbia University, Cornell University, Dartmouth College, Princeton University, University of Pennsylvania, Yale University, and Harvard University. These 8 schools have been recognized as some of the best colleges and universities in the United States.

    Harvard University is a private institution located in Cambridge, Massachusetts. The university includes a number of graduate and professional schools, as well as a college for undergraduates. In 2012, Harvard ranked number one in US News' ranking of national universities again. Founded in 1636, Harvard is the oldest institute of higher education in the United States. It can be said that first there was Harvard, then the United States of America. Also, Harvard's library contains the oldest collection of books in the United States as well as the largest private collection in the world. Harvard has also been described by Forbes Magazine as one of the “billionaire universities” as of their recent list of 469 billionaires, 50 received a degree from Harvard.

    Harvard College (the institute for undergraduate students) is one of the most famous schools in the United States. It offers over 40 undergraduate fields of study, including astrophysics（天体物理学）, mathematics, neurobiology(神经生物学), etc. And the financial aid program there is amazing. Even though the tuition is about 37,576, and there are other expenses throughout the year, about 70% of undergraduate students received financial aid. Out of those students, over 90% of them had their full need met. And the policies for international students are the same for U.S. citizens.

    Harvard College is very selective, as it only admits about 6% of their applicants. For admission into Harvard College, it is required that students take the SAT or the ACT, as well as 2 SAT Subject Tests. Harvard will also look at other factors during admission such as your application essay, high school transcript, work experience, GPA (Grade Point Average), your interview, recommendations, and most importantly, your character and personal qualities.

    Do you like air travel with a service dog? Air travel makes some people very nervous. The crowds, the noise and flying itself can cause unease. But there are classes people can take to help them defeat their fear of flying. And, let me introduce similar training for service dogs that suffer the same problem

Service dogs almost never leave the side of the people they care for. You will see them working on buses, trains and other public transport systems. But the busy environment found at an airport can trouble even the best trained working dog.

    People with disabilities depend on their dogs. They want the animals to safely guide them through security areas. They also need the dogs to remain calm on duty on the plane, even when the flying is not smooth. This takes special training. The Air Hollywood K9 Flight School is one place where such help can be found.

    The school has a piece of equipment that provides the sights, sounds and even the feel of an airplane in flight. It is called a flight simulator, which was built for filming airplane scenes in movies.

    Sandy Alexander has a disability that requires his two-year-old dog, Doc, to be always at his side. Mr. Alexander took the dog to the flight school to get him ready for plane trips. He says Doc did not like the bumpy part of the flight simulation( 模拟).

    Dog trainer Mary Segall is with Canine Companions for Independence. It provides dogs for people with disabilities. Ms Segall says successful training is based on a simple rule: preparation.

    " Dogs need to be exposed gradually and repetitively to stimulation, to the environment, to loud noises, to sounds and to other dogs so that when this experience happens to them on a daily basis, they are  able to act in a way that they're used to acting and that they don't get excitable."

    Dog owners who attended the training at Air Hollywood K9 Flight School say they now feel much more at ease about future flight. Their dogs also seem ready for take-off.

    In some science-fiction movies, robots refuse to die no matter how people fight back (反击). Now, it has turned into a fact. For the first time, researchers have created a robot that can take a beating (挨打) and keep on working. Developed by scientists from Cornell University and the University of Vermont, the new robot looks like a spider with four legs.

    Until now, even the most advanced robot was almost certain to break down when damaged. That's because its computer doesn't know how to operate the machine after its shape has been changed.

    To solve this problem, the scientists put some sensors (传感器) into the machine. The sensors can read how the machine is working and send signals to the computer.

    Using this information, the system follows a new way to tell the machine's shape at any given moment. The computer considers a lot of possible next steps, and it calculates how best to move the robot forward the longest possible distance, before trying to move it again.

    The new technology is a major advance in robotics (机器人技术), scientists say. It may someday help researchers create better artificial arms and legs that give new freedom to people who lack them. The new knowledge might also help scientists understand how people and animals tell their own sense of place in space.

     “Designing robots that can fit changing environments has been a difficult problem,” says scientist Olaf Sporns of Indiana University. “This work provides a new way toward solving this important problem.”

    At the beginning of the century there was a big farm called Hollywood Ranch. It was near Los Angeles in California. A few years later Hollywood was one of the famous places in the world. From the 1910s to the 1950s Hollywood was the film center of the world. Every family knew the names of its film stars—Charlie Chaplin，Greta Garbo，Bergman and hundreds more.

    The reason why people went to Hollywood to make films was the sun. At first people made films in New York on the east coast of the United States. But then they heard about Los Angeles where there are 350 days of sun every year. As they made all the films by sunlight，the west coast was a much better place to work. Also near Hollywood you can find mountains and sea and desert. They did not have to travel far to make any kind of film.

    When TV became popular，Hollywood started making films for television. Then in 1970s they discovered people still went to the cinema to see big expensive films. After twenty years they are still making films in Hollywood and people watch them all over the world.

    A little boy discovered what looked like a map to an unknown place. He soon realized it was the beginning of an exciting treasure hunt.

    He found two pieces of paper along with the mysterious map. One was written with the instructions, “FIND THE WORDS.” The other piece of paper had several strange symbols scattered all over it.

    Dad, fortunately, was there to help his son figure out the mystery. He folded up the paper with the symbols on it, and together they formed a message, which had another set of instructions, “UNDER STEPS.” The smart little boy knew exactly what to do so he went to look under the steps of his house. Without too much effort, he found a box below the staircase.

    It didn't take him long to figure out what to do next: open it up! Inside the box were some very interesting objects, including another piece of a treasure map and two broken pieces of paper. These were the most interesting finds because they contained what appeared to be a collection of letters on them. Finally, they knew where the treasure was from the letters: IN THE BUSH UNDER YOUR YARD.

    After searching all over the yard, following several clues and wondering where everything would lead, the pair finally found what they had been looking for. And it was exactly what you would want after such an adventure: a treasure box!

    The pair pulled it out of the ground and cleaned away all the dirt. The dad put the box in front of his son, and the little boy couldn't contain his excitement. So he opened it up and finally found out what was inside.

    Inside was more treasure than any little boy could ever want. There were hundreds of coins and all sorts of pirate treasure, including what looks like a pearl necklace and some silver dishes.