French surgeons have performed what they said on Wednesday was the world's first partial face transplant— giving a new nose, chin and lips to a woman attacked by a dog.

    Specialists from two French hospitals carried out the operation on a 38-year-old woman on Sunday in the northern city of Amiens by taking the face from a brain-dead woman, who had hanged herself just hours before the operation. Her family agreed on the operation.

    “The patient is in an excellent state and the transplant looks normal,” the hospitals said in a brief statement after waiting three days to announce the pioneering surgery.

    The woman had been left without a nose and lips after the dog attacked her last May, and was unable to talk or chew properly. Such injuries are “extremely difficult, if not impossible” to repair using normal surgical techniques, the statement said.

    The statement did not say what the woman would look like when she had fully recovered, but medical experts said she was unlikely to resemble the woman who had been the source of her new face.

    The operation was led by Jean-Michel Dubernard, a specialist from a hospital in Lyon who has also carried out hand transplants.

    Skin transplants have long been used to treat burns and other injuries, but operations around the mouth and nose have been considered very difficult because of the area's high sensitivity to foreign tissue.

    Teams in France, the United States and Britain had been developing techniques to make face transplants a reality.

    There was a short-term risk for the patient if blood vessels became blocked, a medium-term danger of her body rejecting the new skin and a long-term possibility that the drugs used could cause cancers.

    Experts say that although such medical advances should be celebrated, the transplant had thrown up moral（道德的）and ethical(伦理的) issues. Little is known about the psychological effect of the transplant.

    The poverty line is the minimum income that people need for an acceptable standard of living. People with incomes below the poverty line are considered poor. Economists study the causes of poverty in order to find solutions to the problem.

    As the general standard of living in the country rises, the poverty line does, too. Therefore, even with today's relatively high standard of living, about 10 percent of the people in the United States are below the poverty line. However, if these people had stable jobs, they could have an acceptable standard of living. Economists suggest several reasons why poor people do not have jobs.

    For one thing, more than half of the poor people in the United States are not qualified to work. Over 40 percent of the poor people are children. By law, children less than 16 years old cannot work in many industries. A large number of poor people are old. Many companies do not hire people over 65 years old, the normal retirement age.

    Some poor adults do not look for jobs for a variety of personal reasons: they are sick, they do not have any motivation, they have family problems, or they do not believe that they can find a job.

    Other poor people look for a job, but cannot find one. Many poor adults never went to high school. Therefore, when they look for jobs, they have few skills that they can offer.

    At the present time, the government thinks it can reduce poverty in the country in the following ways:

    First, if the national economy grows, businesses and industries hire more workers. Some of the poor who are qualified to look for jobs may find employment. Then they will no longer below the poverty line.

    Second, if society invests in the poor，the poor will become more productive.

    If the government spends money on social programs, education and training for poor people, the poor will have the skills to offer. Then it is more probable that they can find jobs.

    Finally, if the government distributes society's income differently, it raises some poor people above the poverty line. The government collects taxes from the non-poor and gives money to the poor. These payments to the poor are called welfare.

    Some economists are looking for better solutions to the poverty problem. However, at the present time, many people depend on welfare for a minimally acceptable standard of living.

    Hummingbirds (蜂鸟) are very small birds. This small bird is quite an acrobat (杂技演员). Only a few birds, such as kingfishers and sunbirds, can hover, which means to stay in one place in the air. But no other bird can match the flying skills of the hummingbird. The hummingbird can hover, fly backward and fly upside down!

    Hummingbirds got their name because their wings move very quickly when they fly. This causes a humming sound. Their wings move so fast that you can't see them at all. This takes a lot of energy. These little birds must have food about every 20 minutes to have enough strength to fly. Their favorite food is nectar (花蜜). Nectar is the sweet water deep inside a flower. Hummingbirds use their long, thin bills to drink from flowers. When a hummingbird drinks nectar, it hovers in front of a flower. It never touches the flower with its wings or feet.

    Of all the birds in the world, the hummingbird's colors are among the brightest. Some are bright green with red and white markings. Some are purple. One kind of hummingbird can change its color from reddish-brown to purple to red!

    The hummingbird's nest is special, too. It looks like a small cup. The inside of the nest is very soft. This is because one of the things the mother bird uses to build the nest is the silk from a spider's web (蜘蛛网).

    Every year on April 1, April Fools' Day is celebrated in many countries around the world. In France, it's called "Poisson d' Avril" or "Fish of April." In Scotland, the holiday is often called "Gowkie Day." In Iraq, the holiday is called Kithbet Neesan or "April Lie."

    History experts say people have celebrated April Fools' Day for a long time. Some believe the tradition comes from the ancient Romans more than two thousand years ago. It was a day of playing games and pretending to be someone else.

    Others say the day for fooling began in France in 1564, when King Charles changed the yearly calendar. He moved New Year's Day from April 1 to January 1. Many people did not know about the change because of communication problems back then. Some people continued to celebrate New Year's Day on April 1. Other people called them April Fools and played jokes on them.

    In the United States, April Fools' Day is just a day of joking and playing tricks on friends. These kinds of jokes are also called pranks. These jokes typically end in the prankster shouting "April Fools'!"

    Simple pranks, like telling a friend a funny lie or making prank phone calls, are still common. But, major companies also get in on April Fools' Day fun in a much bigger way. A few years ago, on April 1, Starbucks announced it was introducing new coffee cup sizes -- Plenta and Micra. The very large cups, bigger than a human head, remained useful for customers even after finishing all that coffee. According to Starbucks, the cups could be used as a rain hat, a pot for plants, or a lampshade.

    It did not take long for customers to catch on to the prank! More and more people use social media or smart phone apps to play pranks on their friends on April Fools' Day. One very annoying smart phone app, Cat Facts, sends funny facts about cats to your friends' phones, every day.

    There exist cruel wars, fighting and sadness in the world today, so it's not only necessary, but also essential to have a good sense of humor just to help us go through difficult times in our lives. Putting a smile on someone's face when you know they are feeling depressed, as the saying goes, makes me feel good and warms my heart.

    How would you feel if you could not joke around with wife, husband, child, co-worker, neighbor, close friend, or even just someone that you are standing in line with at your corner store? I am always saying things that make others smile or laugh, even if I don't know the person I'm joking around with. My Grandma always found humor in everything she did, even if it was the hardest job anyone could imagine. This not only relieves stress in any situation, but also is a common manner to speak to others that are around you.

    I know of a few people that don't have a funny bone in their bodies, as they say. Everyone around them could be rolling on the floor after hearing a great joke and they would sit there without the slightest smile on their faces. They don't get the joke that makes others laugh. I am, laughing hard while they just sit there, looking at me as if I were from outer space. How can people not get a really funny joke?

    Laughing is essential to keep your stress levels under control. Without humor, we would find ourselves with a lot of psychological problems, or on a lot of medications to keep us from going crazy. There is too much sadness and bring a little light into our lives. Therefore, I believe our best medicine is to get together and tell some jokes and have some fun laughing together.

High on the Qinghai-Tibet Plateau {#blank#}1{#/blank#}(lie) China's "water tower" Sanjiangyuan. It is home to the headwaters of China's three rivers: the Yellow River, the Yangtze River, and the Lancang River. It is the three rivers {#blank#}2{#/blank#} provide water for about half the population of China. However, human activities are putting this ecosystem {#blank#}3{#/blank#} risk. Hopefully, though, we can repair this damage. In 2016, the Chinese government established Sanjiangyuan National Park in Qinghai Province. The park, {#blank#}4{#/blank#}(schedule) to open in 2020, has increased the area's green coverage and attracted more wildlife. The local government has also made great efforts to improve biological diversity. The success of Sanjiangyuan will mark the start of a {#blank#}5{#/blank#}(green) future. With Sanjiangyuan {#blank#}6{#/blank#}(take) the lead, nine other regions in China{#blank#}7{#/blank#}(choose) by a field conservation station to carry out projects over the past three years, {#blank#}8{#/blank#} will form a national park system together. The idea of a national park system is still new in China, but {#blank#}9{#/blank#}(it) realization is urgent. After all, building an ecological civilization bears great {#blank#}10{#/blank#}(important) in the development and progress of human civilization.