Years ago I moved to Woodland Hills to take a job in a small hospital's emergency department. No one wanted to work on Christmas Eve, so the shift（轮班）went to me. I kissed my family goodbye and went off to spend the night in the hospital. It was a thankless job.

    At 9 pm, the ambulance brought in a man in his 60s who was having a heart attack. His face was pale, and he was frightened. The whole night I did my best to save his life. Before I left in the morning to spend Christmas with my family, I stopped by to see how he was doing. It was still tough, but he had survived the night and was sleeping.

    The following year I got Christmas Eve duty again. At 9 pm sharp, the ward clerk told me there was a couple who wanted to speak with me. When I approached them, the man introduced himself as Mr. Lee and said, “You probably don't remember me, but last Christmas Eve you saved my life. Thank you for the year you gave me.” He and his wife hugged me, handed me a small gift, and left.

    The following year a new doctor had joined the group, but I wanted to see if Mr. and Mrs. Lee would return. This time, I volunteered for the shift. I kept an eye on the door. Once again, at exactly 9 pm, the Lees appeared, carrying a warmly wrapped bundle. It was their new grandchild. Mr. Lee, his family and I spent 13 Christmas Eves together.

    The last year I saw him, he brought me a gift. I carefully opened the package and found a crystal bell inside. It was carved with a single word: Friendship. Now, my family, friends and I ring that bell every Christmas Eve at exactly 9 pm and offer our best wishes to the man who we won't forget.

    Don't you hate it when someone snubs（冷落）you by looking at their phone instead of paying  attention? The word “Phubbing”, which comes from “phone” and “snub”, describes such behavior. With popularization of smart phones, we see a new "Phubbing" group everywhere in public places: in subway, restaurants, roads, people are checking the mobile phone, ignoring the people around completely. What is worrying us is that not only young people, but also the elderly and kids are getting addicted（上瘾）to Phubbing.

    On Dec 29th, a 28-year-old woman—a mother of two in Wenzhou, drowned after she fell into a river while looking at her mobile phone. A Pakistani man was killed on Dec 15th, 2015, after being hit by a fast moving train while trying to take a selfie (自拍)with it on the track. Last month, Justin, a college student was shot in subway in San Francisco, the U.S. The surveillance(监控)video showed that before Justin was killed, the killer pulled out the gun several times, and even wiped his nose with it. However, nobody noticed that. The surrounding passengers all focused on their cell phones.

    Phone is the tool for communication, but now it distances people and makes them separated from each other. Therefore, someone jokes “the furthest distance in the world is not the distance between life and death, but that you don't know I stand in front of you while you focus on the mobile.”

    Phubbing appears harmless; however, it does affect our life. 23-year-old Alex from Melbourne wrote in his blog: "I can no longer focus on what I am eating since I started twittering. My skill of food photography has improved very fast, while my interest in food drops a lot as a result."

    Good health is the most valuable thing a person can have, but one cannot take good health for granted. It is important to remember that the body needs proper care in order to be healthy. There are three things that a person can do to help stay in good: eat right food, get enough sleep, and exercise regularly.

    Proper nutrition is important for good health. Your body cannot work well unless it receives the proper kind of “fuel”. Don't eat too much food with lots of sugar and fat. Eat plenty of foods high in protein, like meat, fish, eggs and nuts. Vegetables and fruits are very important because they provide necessary vitamins and minerals. However, don't overeat. It is not helpful to be overweight.

    Getting the proper amount of sleep is also important. If you don't get enough sleep, you feel tired and easily get angry. You have no energy. Over along period of time a little amount of sleep may even result in a change of personality. Be sure to allow yourself from seven to nine hours of sleep each night. If you do, your body will feel strong and refreshed, and your mind will be sharp.

    Finally, get plenty of exercise. Exercise firms the body, strengthens the muscles, and prevents you from gaining weight. It also improves your heart and lungs. If you follow a regular exercise program, you will probably increase your life-span. Any kind of exercise is good. Most sports are excellent for keeping the body in good shape: basketball, swimming, bicycling, running and so on are good examples. Sports are not only good for your body, but they are enjoyable and interesting, too.

    If everybody were to eat the right foods, get plenty of sleep and exercise regularly, the world would be a happier and healthier place. We would all live to be much older and wiser.

    A good teacher is many things to many people. In my own experience, the people I respect the most and think about the most are the teachers who demanded the most discipline (纪律) from their students.

    I miss one teacher in particular that I had in high school. I think she was a good teacher because she was a very strict person. I remember very clearly a sign on her classroom door. It was a simple sign that said,    "Laboratory: in this room the first five letters of the word was stressed not the last seven." In other words, labor for her was more important than oratory, which means making speeches.

    She prepared her work very carefully and told us to do the same. We got lots of homework from her. Once she had broken her arm, and everybody in the class thought that maybe the homework load would be reduced, but it continued just the same. She checked our work by stamping her name at the bottom of the papers to show that she had read them.

    I think sometimes teachers who demand the most are liked the least. But as time goes by, this discipline really seems to benefit the students.

    Street art is a very popular form of art that is spreading quickly all over the world. You can find it on building, sidewalks, street sings and trash cans from Tokyo to Paris, and from Moscow to Cape Town. Street art has become a global culture and even art museums and galleries are collecting the works of street artists. Even advertising companies also use street art in their ads due to its popularity.

    Street art started out very secretly because it's illegal to paint on public and private property without permission. People often have different opinions about street art. Some people think it is a crime with others think it's a new form of culture.

    Art experts claim that the movement began in New York in the 1960s. Young adults sprayed words and images on walls and trains. This colorful and energetic style of writing became known as graffiti(涂鸦). Graffiti art showed that young people wanted to rebel against society. They didn't want to accept rules, and they travelled around cities to create paintings that everyone could see. In many cases, they had trouble with the police and the local government.

    Many street corners in Paris show the works of Space Invader. A French artist uses small pieces of glass to make images of space creatures. He has been doing this for some years and the police have arrested him a few times. On his website, you can see many other places where he has created this form of art.

    Street artists do their work for some reasons. Some of them do not like the artists who make so much money in galleries and museums. They choose street art because it is closer to common people. Some artists try to express their political opinion in their works. They often want to protest against big firms and corporations. Others like to do things that are forbidden and hope they don't get caught.

    In today's world, the Internet has a big influence on street art. Artists can show their pictures to people all over the world. Many city residents, however, say that seeing a picture on the Internet is never as good as seeing it alive. The street art movement lives with the energy and life of a big city. There it will continue to change and grow.

    The world's insects are going down the path of extinction, threatening a "catastrophic collapse of nature's ecosystems", according to the first global scientific review. More than 40％of insect species are declining and third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles.

    "It should be of huge concern to all of us, for insects are at the heart of every food web. They pollinate (授粉) the large majority of plant species, keep the soil healthy, recycle nutrients, control pests, and much more. Love them or 1oathe them, we humans cannot survive without insects, "said Prof Dave Goulson at the University of Sussex in the UK.

    The analysis, published in the journal Biological Conservation, says intensive (集约型) agriculture is the main driver of the declines, particularly the heavy use of pesticides. Urbanisation and climate change are also significant factors.

    "If insect species losses cannot be stopped, this will have catastrophic consequences for both the planet's ecosystems and for the survival of mankind. It is very rapid. In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none," said review author Francisco Sánchez-Bayo, at the University of Sydney, Australia.

    One of the biggest impacts of insect loss is on many birds, reptiles, amphibians and fish that eat insects. "If this food source is taken away, all these animals starve to death," he said. Such effects have already been seen in Puerto Rico, where a recent study revealed a 98％fall in ground insects over 35 years.

    Matt Shardlow, at the conservation charity Buglife, said: "It is thoughtful to see this evidence that shows the pitiful state of the world's insect populations. It is increasingly obvious that the planet's ecology is breaking and there is a need for a strong and global effort to prevent and change these terrible trends."