We once had a poster competition in our fifth grade art class.

    “You could win prizes,'' our teacher told us as she wrote the poster information on the blackboard. She passed out sheets of construction paper while continuing, “The first prize is ten dollars. You just have to make sure that the words on the blackboard appear somewhere on your poster.”

    We studied the board critically. Some of us looked with one eye and held up certain colors against the blackboard, rocking the sheets to the right or left while we conjured up our designs. Others twisted their hair around their fingers or chewed their erasers while deep in thought. We had plans for that ten-dollar grand prize, each and every one of us. I'm going to spend mine on candies, one hopeful would announce, while another practiced looking serious, wise and rich.

    Everyone in the class made a poster. Some of us used parts of those fancy paper napkins, while others used nothing but colored construction paper. Some of us used big designs, and some of us preferred to gather our art tidily down in one corner of our poster and let the space draw the viewer's attention to it. Some of us would wander past the good students' desks and then return to our own projects with a growing sense of hopelessness. It was yet another grown-up trick of the sort they seemed especially fond of, making all of us believe we had a fair chance, and then always — always — rewarding the same old winners.

    I believe I drew a sailboat, but I can't say that with any certainty. I made it. I admired it. I determined it to be the very best of all of the posters I had seen, and then I turned it in.

    Minutes passed.

    No one came along to give me the grand prize, and then someone distracted me, and I probably never would have thought about that poster again.

    I was still sitting at my desk, thinking, What poster? when the teacher gave me an envelope with a ten-dollar bill in it and everyone in the class applauded for me.

    When my sister Gina was born, she had a problem with her heart. Her heart was pretty bad in the beginning and she stayed in the hospital for a month. The first few years were very difficult because she was very sick. She had five operations before she was three years old. She had trouble walking, playing with other children, and going to school.

    Although Gina couldn't laugh and talk, we all knew that she just needed love and care. Our parents wanted to take Gina to a special place in Florida where she could swim with dolphins. Gina was afraid of swimming with them because she had never been around dolphins before. We had also never traveled that far as a family.

    When we got to Florida, we saw where the dolphins lived. It was a place where kids with special needs like Gina could come and spend time. I thought it was going to be a vacation, but it wasn't. Gina had to work hard every day for a week.

    The trip was amazing .Gina laughed and clapped(拍手) when she saw the dolphin, and the dolphin splashed (溅起水花) when it saw Gina. They swam together all day. Gina was able to move her body more than she normally did at home. Mom and dad were proud of Gina. I was, too.

    Self-driving vehicles(车辆) will rely on cameras, sensors and artificial intelligence (人工智能) to recognize and respond to road and traffic conditions, but sensing is the most effective for objects and movement in the neighborhood of the vehicle. Not everything important in a car's environment will be caught by the vehicle's camera. Another vehicle approaching at high speed on a collision (碰撞) track might not be visible until it's too late. This is why vehicle-to-vehicle communication is undergoing rapid development. Our research shows that cars will need to be able to chat and cooperate on the road, although the technical challenges are still great.

    The usages of vehicle-to-vehicle communication contain vehicles driving together in a row, as well as safety messages about nearby emergency vehicles. Vehicles could alert each other to avoid collisions or share notices about passers-by and bicycles. From as far as several hundred metres away, vehicles could exchange messages with one another or receive information from roadside units（RSUs）about nearby incidents or dangerous road conditions through 4G network. A high level of AI seems required for such vehicles, not only to self-drive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategize and adapt according to information received in real time and to carry out cooperative behaviors. For example, a group of autonomous vehicles might avoid a route together because of possible risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

    Further applications(应用) of vehicle-to-vehicle communication are still being researched, including how to perform cooperative behavior.

    For many people who live in cities, parks are an important landscape. They provide a place for people to relax and play sports, as well as a shelter from the often severe environment of a city. What people often overlook is that parks also provide considerable environmental benefits.

    One benefit of parks is that plants absorb carbon dioxide and give off oxygen. According to one study, an acre of trees can absorb the same amount of carbon dioxide that a typical car emits in 11,000 miles of driving. Parks also make cities cooler. Scientists have long noted what is called the Urban Heat Island Effect: building materials such as metal and concrete (混凝土) absorb much more of the sun's heat and release it much more quickly than trees and grass. Because city landscapes contain so much of these building materials, cities are usually warmer than surrounding rural areas. Parks and other green spaces help to lessen the Urban Heat Island Effect.

    Unfortunately, many cities cannot easily create more parks. However, cities could benefit from many of the positive effects of parks by encouraging citizens to create another type of green space: rooftop gardens. While most people would not think of starting a garden on their roof, human beings have been planting gardens on rooftops for thousands of years. Some rooftop gardens are simple container gardens that anyone can create with the investment (投资) of a few hundred dollars and a few hours of work.

    Rooftop gardens provide many of the same benefits as other urban parks and garden spaces, but without taking up the much-needed land. In the summer, rooftop gardens prevent buildings from absorbing heat from the sun, which can significantly reduce cooling bills. In the winter, gardens help control the heat that materials like brick and concrete release so quickly, leading to savings on heating bills. Rooftop vegetables and herb gardens can also provide fresh food for city settlers, making their diets healthier. Rooftop gardens are not only something everyone can enjoy but also a smart environmental investment.

    Saber Miresmailli was on vacation in London when, caught in a bit of traffic on London Bridge, he decided to take a photo of Tower Bridge.

    “I noticed the couple,” he said. “At that moment, I did not see anyone from the wedding party or a photographer with the couple, so I took several pictures. Usually, my pictures are not very good given the fact that I don't use flash and I don't stop to compose (构图)-so when we get back after two weeks, I was very surprised to find this one turned out so well.”

    Miresmailli said, “I thought to myself, if it was me getting married, I would have wanted the picture.” So he posted the photo on Facebook and attached a few friends with the hope of finding the couple and passing them the picture. What happened next, he said, “was crazy”. “I received more than 2,000 requests from perfect strangers and lots of positive and negative emails.” Until this afternoon, almost 230,000 people had shared his Facebook post on the photo.

There's also been an uncertain identification of the couple. It's likely that their names are Laura and James. “If it's the right couple,” Miresmailli said, “they are on their honeymoon in Bali and have no idea about the photo. I believe they will be shocked to find out about their fame.”

    Miresmailli said he's been drowned by the interest in the photo. “I just want to give them their picture and go back to work and tend my tomatoes,” he said.

    Christmas is a time for eating great food, giving and receiving presents, and most importantly spending time with your family watching some classic Christmas movies.

The Grinch (2000)

    This is a Christmas must-watch and one of Jim Carrey's best performances. It was also originally a nursery tale book written by Dr Seuss. It's the story of a green monster who wants to ruin Christmas but who in the end discovers the power of love and generosity. I promise it's a great film with plenty of laughs along the way.

    Love Actually (2003)

    While this is not a personal favourite of mine, people in the UK absolutely love this film. It has many featuring actors and actresses. It might be a little difficult to follow as there are complex plots, so I recommend watching a translated version or enabling subtitles (字幕) in your native language. However, the heart-warming elements of the film make it worth watching.

    Home Alone (1990)

    This amusing masterwork is one of my favourite films of all time. It tells the story of a boy, Kevin, who is left alone in his house when his large family forgets to take him on vacation with them. While the families are away, burglars try to rob the house and Kevin must protect his home by setting traps. The trips, falls and traps will have you laughing out loud as you watch a 10-year-old boy beat two grown men.

    Miracle on 34th Street (1994)

    You can't have Christmas in an English-speaking country without watching this movie. It's not funny like Home Alone or The Grinch, but it is incredibly touching. It's about a man who claims to be Santa, but nobody believes him except a lawyer and a little girl. The story-line may seem a little childish but you can enjoy it at any age.