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.

    They may be teenagers, but 17-year-old Brittany Bull and 16-year-old Sesam Mngqengqiswa have grand ambitions(雄心) — to launch Africa's first private satellite (卫星) into space. They are part of a team of high school girls from Cape Town, South Africa, who have designed and built equipment for a satellite that will orbit over the earth's poles scanning Africa's surface.

    Once in space, the satellite will collect information on agriculture, and food security within the continent. Using the data/we can try to determine and predict (预测) the problems Africa will be facing in the future”, explains Bull, a student at Pelican Park High School.“Where our food is growing, where we can plant more trees and vegetation and also how we can monitor remote areas,” she says. “We have a lot of forest fires and floods but we don't always get out there in time.'' Information received twice a day will go towards disaster prevention.

    It's part of a project by South Africa's Meta Economic Development Organization (MEDO) working with Morehead State University in the US.

The girls (14 in total) are being trained by satellite engineers from Cape Peninsula University of Technology, in an effort to encourage more African women into STEM (science, technology, engineering, mathematics).

    Scheduled to launch in May 2017, if successful, it will make MEDO the first private company in Africa to build a satellite and send it into orbit.

    Mngqengqiswa comes from a single parent household. Her mother is a domestic worker. By becoming a space engineer or astronaut, the teenager hopes to make her mother proud. “Discovering space and seeing the Earth's atmosphere, it's not something many black Africans have been able to do, or get the opportunity to look at I want to see and experience these things for myself,” says Mngqengqiswa.

    Her team mate Bull agrees, “I want to show to fellow girls that we don't need to sit around or limit ourselves. Any career is possible-even aerospace.”

    It is quite apparent that competition surrounds every aspect of human life whether in the United States or the Amazon Rain Forest. Without it we would not have grown into primates(灵长类动物). Or we would probably still be struggling to sharpen a bronze tool while crawling around on four legs in search of meat. Without competition, Columbus wouldn't have discovered America and Edison would never have invented the light bulb.

    Friendship, like all relationship between two people, involves competition. It isn't competition in a traditional sense because there are no goals to be scored and no prize. Perhaps the ecological definition—the simultaneous (同时的)demand by two or more organisms for limited environmental resources, such as nutrients， living space, or light- better explain it.

    As in nature, high school life is governed by a set of laws, similar to a shortened version of Darwin's theory of evolution, overpopulation, and competition. There is an abundance of high school students and to distinguish them, ranking and categorizing(分类)take place. In high school, friendships learn to co-exist with competition even though at times the relationship is rough. In fact, in some circumstances, competition is too much of a burden for a friendship to bear, causing it to fall apart. College admission is the final high school objective. Four years of hard work is to achieve good grades, and a student's fate is determined not only by these achievements, but by the records of thousands of other seniors trying to achieve a similar recognition.

    Nevertheless, by necessity, competition between students exists in all aspects of high school life. It sets and improves the standards in everything from sports to school work. A healthy, friendly competition can have only benefits, but when it becomes too fierce, jealousy can tear friendships apart. Yet, despite all this, without competition, we would be lost.

    The arts, especially music, should be part of every school's lessons at every grade level. Students would be much smarter if they had some musical experience. They could improve their classroom skills, like paying attention and following directions. People develop all these skills when they learn music. Making music also lets children use their imagination. It provides students with a chance to try out their own ideas.

    Music not only makes children better students, but also gives them something positive to do. In a music program, children can be part of a band instead of joining a gang (团伙). Parents can enjoy listening to their children's music instead of seeing them glued to a computer or TV screen. In a school band, students get to be part of a team. They can get along well with old friends and make new friends through music.

    Music builds self-confidence, too. It gives children a sense of achievement and success. Making music is something for them to be proud of, and it lets kids practice performing in front of an audience. Music gives children an opportunity for self-expression, and that helps develop their self-confidence.

    Once again, music is important because it can make children better students, give them something positive to do, and build their character. That is why music should be offered in every single grade in every school.

    Going back to school can be an anxious time for many students. But one institution in Texas is doing its part to make sure middle schoolers are returning refreshed and inspired to learn.

    Through a process called the "bathroom inspiration project," teachers and administrators at Warren Middle School, spent their summer beautifying the school's restrooms by painting motivational murals (壁画) on each of the stalls (小隔间).Forming messages like "Your mistakes don't define you" and "Scatter (撒播) kindness," the brightly colored words are exactly what a young student needs to see when having a rough day-or any school day for that matter. And now that classes are officially in session, people are already noticing a positive impact.

    Since posting photos of upgrades to the school in July, Principal Joshua Garcia says that the alterations have aroused a great response.

    "Students have been talking about the murals from the moment the pictures had been posted. Some even took the time to find a reason to come up to the campus to see the murals," he says." I think what makes this small little action so valuable is that it has set the tone for our campus."

    And not only is that important to students, parents, and fellow staff, but it is also vital for the school's new principal, who is trying to gain the trust of the community during a time in which trust is so necessary for schools.

    "Being new to the campus, I think the parents were able to see how much I value their children and have their best interest at heart," Garcia continues. "I have had many parents tell me how they can just feel a difference in the campus climate and how much they are enjoying seeing their children wanting to come here. These murals have put trust back in the campus and its teachers, and by doing so we are able to build a culture in which our students want to be here and learn."

Even though they're not the most exciting things in the world, plants have fascinated us ever since the days of early humans. They may not do any tricks or greet us when we come home at night like a dog would, but that doesn't mean they're any less interesting than animals.

However, just when we thought we knew everything we could about them, a recent study found that plants may possess a secret ability that's gone unnoticed all this time. According to the study by Australian biologist Monica Gagliano, published in the journal Oecologia, plants may be able to hear sounds.

To come to this conclusion, Gagliano and her team planted pea seedlings in a pair of different Y-shaped pots with two arms. The first pot's arms led to fresh water, while the other's led to either dry soil or a sealed plastic tube containing flowing water.

Naturally, the first pot's seedlings grew toward the water. What's surprising, however, is that the second pot's seedlings grew toward the sealed water supply and not the soil.

They just knew the water was there, even if the only thing to detect was the sound of it flowing inside the pipe, Gagliano told Scientific American. Gagliano believes that plants are able to use their leaves to detect sound waves, which make tiny vibrations (振动) as they're produced.

This could explain why so many people believe that singing or playing music to their plants helps them grow.

I had a plant that I used to wash the leaves once a week and sing to it, plant lover Heather Goodall told BBC News. It grew from being about 2 feet tall to 7 feet tall in just a couple of years.

So, does this mean we should start treating our plants like pets? Not necessarily, although perhaps it does mean we should give them more respect. I would like to see plants acknowledged more as the amazing, interesting, exotic living beings they are, and less as a mere source of human nutrition, Fatima Cvrckova, a scientist at Charles University in the Czech Republic, told BBC News.