Unlike most other holidays, the history of April Fools' Day. Sometimes called All Fools' Day, is not as the totally clear. The only point in time that can be agreed on as the beginning of this tradition was 1582,in France. Before that year, the New Year was celebrated for eight days, beginning  on March 25.The reform of the calendar celetxration reached the highest point on April l_With the riform of the calendar under Charles 1X,the Gregorian calendar (公历, 阳历）was introduced, and New Year's Day was moved to January 1.

    However, because in those days communications were not as developed as they are today, many people did not receive the news for several years. Some people refused to accept the new calendar and continued to celebrate the New Year on April, These backward people were considered “foots” by other peopk. They were often sent on “fools” errands (徒劳无益的工作)or were made the taragets of jokes.

    This developed, over time, into a tradition of playing a trick on someone on the first day of April. The tradition eventully spread to England and Scotland in the eightreenth century. It was later introduced to the American colonies of both the Britain and Francc.April Fools' Day thus developed into an  international fun feast,so to speak,with different nationalities specializing in their own kind of humor at the expense of their friends and families.

    For nearly a century before there was such a thing as a space program, a view of space was possible. People could see full views of the Moon, explore Mars(探测火星),and study the outer space beauty. All of this was made possible by a small group of artist-astronomers(天文艺术家) who worked to show people how other worlds in space might look.

    Lucien Rudaux, a French artist, was the first to use his artistic ability and his knowledge of astronomy in art. His paintings show a mixture of skilled observations, brilliant imagination and careful attention. As a result, many of his works have come surprisingly close to actual conditions on distant planets. His painting of Mars included moonlike craters(火山口) that were first photographed by the astronauts in 1965. His 1930 painting of a dust storm looks remarkably like a photograph of a storm taken by the astronauts in 1976.

    The artist-astronomers, including Rudaux, made people interested in outer space by painting what turned out to be exact portraits of the planets.

    The number of giraffes is becoming smaller across Africa, according to the Giraffe Conservation Foundation. The total population has dropped by 40 percent in the last 15 years. Surprisingly, even scientists haven't given much attention to giraffes. We are learning more about their ecology, but what we know is still way behind what we know about other species. "It's a silent extinction," said Dr. Julian Hennessy, a wildlife scientist.

    "The main reason for the smaller number of giraffes is their loss of living places," said Hennessy, "as an increasing part of land is used for farming. But hunting also has a big influence." You might wonder why hunters would focus on giraffes. First of all, once a giraffe is brought down, there is lots of meat with a small amount of effort. Besides, there is another thing encouraging the hunting. In Tanzania, Hennessy says, the latest word on the street is that eating giraffe meat could cure AIDS. Fresh giraffe heads and bones can be sold at prices of up to $140 per piece.

    Another widespread misconception about giraffes is that they are everywhere. Look at kids' books which are full of giraffes. They are always in zoo collections. They can be seen easily, so you don't think we have to worry about them. But the truth is that they are in danger of extinction. There is a lack of right and true data.

    Hennessy and other researchers are now pulling together the data needed to improve the situation of the entire giraffe species and all nine subspecies (亚种). The information will be used to change the giraffe's listing on the International Union for Conservation of Nature Red List, which now lists the species as of "least concern" but two subspecies as "endangered". "It's a lot of work to gather the necessary information," Hennessy says. "And several other giraffe subspecies will be recommended for endangered listings next year or the year after." He hopes that the world will finally start to take notice of how endangered these beloved animals have become.

    The clock always seems to be ticking rather too fast in the doctor's office and the queue of patients outside the door seems to be pressing rather too hard. Some say it's high time for the model of short, sharp one-to-one appointments to give way to shared medical appointments (SMAs).

    SMAs are doctor-patient visits in which a group of patients receive patient education and counseling (咨询),physical examination and medical support in a group setting. Typically SMAs are designed to have one or more doctors attend to a group of patients who share a common illness or medical condition. In contrast to one-to-one visits, SMAs provide a longer appointment time-frame as well as the opportunity for patients to have improved access to their physicians and meanwhile pick up additional information and support from peers.

    However, doctors who have pioneered the shared appointment approach report that there are significant challenges involved. Dr. Sumego, director of shared medical appointments, Cleveland Clinic, identifies culture change as the most significant challenge. Physicians and nurses are trained in a model of personal service and privacy; the SMA approach is a fundamental challenge to those fixed ideas. They need shared goals and a way of testing the innovation against agreed standards. Dr. Sumego says, "The physicians may be worried about the possible chaos and efficiencies that are marketed. They also have to make the patients understand what their appointment is, and what the expectation is."

    "So, if an organization was looking to start shared medical appointments, I would advise them to start the buy-in from a few champion physicians, develop the work-flow and develop some experience. Provide some support behind what that best practice should look like. Create some standards so that, as the concept spreads, you can employ that experience to start the next shared medical appointments and the next."

    The saying, "Don't judge a book by its cover, means you should not guess the worth or value of something based on how it looks. That message was clear at a recent event called the Human Library Project. The event took place at the Northern Virginia, or NoVa, Community College, outside of Washington. D. C.

    The Human Library began 19 years ago in Denmark. It grew from a youth organization called "Stop the Violence". Today, it is a worldwide movement. At the NoVa event, students got the chance to learn from a person—a "human book"—instead of a library book.

    Patricia Cooper organized the event. She said that human books celebrate variety by telling their life stories in an easy-going setting. "The goal of the human library is to talk to people in your community who you may otherwise not speak to because you have your own prejudices (偏见) and hopefully to break down some of these barriers."

    This is the third year that NoVa has held such an event. The collection of human books included a civil rights activist, a scientist from the American space agency NASA, and an opera singer.

    Artist Brian Dailey was a human book. He spoke about his travels to 113 countries in seven years. Dailey said that, during his travels, he asked people whom he took pictures of for a one-word answer to a series of other words—such as love, freedom and war. He discovered that people in different countries often had very different reactions to the same word.

    When Dailey asked people in Africa about the word "war" they used words like justice, liberation and peace. When he asked the same question to people in Syrian refugee camps, the answer was: "tears, hunger, fear, destruction".

    Ask any new college graduate about his immediate goals, and it is likely that he will tell you he wants a job. But it turns out that today's students are not going to be satisfied with any job. According to the latest survey, making a difference through their work is essential (必要的) to young people's happiness.

    The survey found that 72 percent of graduating college seniors believe being able to have a positive social influence through their work is essential to their happiness. Making a difference is so important to them that 45 percent say they would take a 15-percent pay cut to work at an organization that has a social or environmental influence, and 58 percent say they would take a pay cut to work for an organization whose values are the same as their own.

    Besides this, the survey found that female students are far more likely to put social influence in first place than their male classmates, echoing the results of a former study showing that female maths and science majors are more likely to say they go into those fields to make a difference.

    One reason for the emphasis (强调) on improving the world probably has to do with the culture of colleges, which encourages students to connect their studies back to real-world problems. Students are used to discussing important social issues (问题) with their friends and professors, and doing something about them in class or through volunteer activities. Once students develop those habits, they don't shut them off when graduation rolls around.