A qualified doctor who rarely practicedbut instead devoted his life to writing．He once said: “Medicine is my lawfulwife, and literature is my lover．” Russian writer Anton PavlovichChekhov, was a great playwright and one of the masters of the modern shortstory．

When Chekhov entered the MoscowUniversity Medical School in 1879, he started to publish hundreds of comicshort stories to support his family．After he graduated, he wrote regularlyfor a local daily newspaper．

As a writer he was extremely fast, oftenproducing a short story in an hour or less．Chekhov's medical and science experiencecan be seen through the indifference (冷漠) many of his characters show to tragicevents．In1892, he became a full time writer and published some of his most memorablestories．

Chekhov often wrote about the sufferingsof life in small town Russia．Tragic events control his characters whoare filled with feelings of hopelessness and despair．

It is often said that nothing happens inChekhov's stories and plays．He made up for this with his excitingtechnique for developing drama within his characters．Chekhov'swork combined the calm attitude of a scientist and doctor with the sensitivity(敏感) of anartist．

Some of Chekhov's works were translatedinto Chinese as early as the 1940s．One of his famous stories, The Man in aShell, about a school teacher's extraordinarily orderly life, was selected as atext for Chinese senior students．

    Self-driving vehicles will rely on cameras, sensors and artificial intelligence（AI）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 considerable.

    Applications for vehicle-to-vehicle communication range from vehicles driving together in a row, to 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 A1 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 in the light of information received in real time and to carry out cooperative behaviours. For example, a group of autonomous vehicles might avoid a route together because of potential risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

    Further applications of vehicle-to-vehicle communication are still being researched, including how to perform cooperative behaviour.

    He wishes the holiday season would end already. His back aches, his red suit feels like a spacesuit, his cheeks have gone tight from smiling for 12 hours—and still the kids keep coming and coming, like ants at a picnic. As Christmas becomes more commercialized (商业化) across the U. S. and Canada, so must Santa Claus. As the holiday begins earlier each year, so must its spokesmen.

    The questions from children these days are harder than ever. Now, with thousands of children expecting a father or mother serving in Iraq or Afghanistan, the questions are as heart­breaking as they are unanswerable. For example, “Can you please bring Daddy home from the war in time for Christmas morning？”

    Santa Claus; also have a pretty good chance of getting sued (指控). A professional Santa Claus in Canada told a story: A Santa had a girl on his knee, and he commented, “You have nice eyes and nice hair.” The girl later said it was sexual harassment (骚扰). When a Santa feels anxious, he often shows it in the same ways ordinary people do. The Santa Claus were always seen to hang around at the dinner table when the show ended. Many of them just sleep in bed for several days and don't see other children again.

    Melissa Poe was 9 years old when she began a campaign for a cleaner environment by writing a letter to the then President Bush.Through her own efforts,her letter was reproduced（复制）on over 250 donated billboards（广告牌）across the country.

    The response to her request for help was so huge that Poe established Kids For A Cleaner Environment(Kids F.A.C.E.) in 1989. There are now 300,000 members of Kids FACE worldwide and is the world's largest youth environmental organization.

    Poe has also asked the National Park Service to carry out a "Children's Forest" project in every national park. In 1992, she was invited as one of only six children in the world to speak at the Earth Summit in Brazil as part of the Voices of the Future Program. In 1993, she was given a Caring Award for her efforts by the Caring Institute.

    Since the organization started, Kids F.A.C.E.members have distributed and planted over 1 million trees! Ongoing tree-planting projects include Kid's Yards—the creation of backyard wildlife habitats and now Kids F.A.C.E.is involved in the exciting Earth Odyssey, which is a great way to start helping.

    "Starting the club turned out to be a way to help people get involved with the environment. Club members started doing things like recycling, picking up litter and planting trees as well as inviting other kids to join their club."

    "We try to tell kids that it's not OK to be lazy," she explains. "You need to start being a responsible, environmentally friendly person now, right away, before you become a resource-sucking adult."

    Here are some schools in Southeast England. Find out if you are interested in any of them.

    Fashions have a lot of rules. Most of them, however, are just wrong. But there's one rule that goes beyond tradition and into the field of scientific study of the brain: Black garments are slimming. It all comes down to how your visual system processes the light. The below holes in each square are the same in size, yet the white hole looks bigger than the black hole.

    In the 1500s, Galileo Galilei noticed that some of the planets looked larger when viewed with the naked eye (肉眼) than they did when viewed through a telescope, making the white light of Venus (金星) appear eight to ten times larger than Jupiter (木星) in the night sky. He knew something strange must be going on with his vision to cause this illusion, but he wasn't sure what it was. Luckily, scientists never stopped wondering, and in 2014, they figured it out.

    Our visual system operates via two main channels: "on" neurons (神经元) that are sensitive to light things and "off" neurons that are sensitive to dark things. When it came to the dark "off" neurons, the researchers found that they responded predictably to dark shapes on a light background — the greater the contrast between the two, the more active these neurons were. But the light "on" neurons behaved unpredictably. Even with the same amount of contrast, light objects on a dark background caused a greater response in these neurons.

    This makes some sense, evolutionarily speaking. In the dark of night, you'd want to be able to take in every bit of light you can get, so a visual system that enlarges light objects on a dark background could be very useful. However, it's not that hard to see dark objects in the light of day. It has some effects in the colors of your clothes and in the appearance of the planets—the brighter appearance of Venus in the night sky makes it look bigger than the darker Jupiter.