Do you often feel lonely? What do you do when you feel that way? Hide yourself away and spend your time reading, watching TV or walking around?

    You might think that feeling lonely is just like feeling happy, sad or scared — that it's just one of your various moods. That is true. However, if you let yourself be lonely for too long without dealing with it, you could be making a serious mistake.

    Doctors have known for some time that feeling lonely is bad for the mind. It can lead to mental health problems such as depression, stress and reduce confidence. "Being lonely means not feeling connected or cared for, but it's not about being mentally alone," Lisa Jaremka, scientist from Ohio State University, US, told Live Science in January. And there's growing evidence that not having friends is connected with physical illness as well.

    In 2006, for example, scientists studied 2,800 women who had cancer. They found that those who had few friends or family were five times more likely to die of their disease than women with many social contacts. Also, even healthy people had a better chance of falling ill if they felt left out by others, according to the BBC.

    The results have scientists thinking that loneliness might hurt the immune system（免疫系统）, which protects the body from diseases.

    Hoping to prove this theory, Jaremka and her research team put volunteers（志愿者） through a stress test. During the test, volunteers were asked to make an unprepared speech in front of a group of stony-faced people. The researchers found that volunteers who said they were lonely in their daily lives felt more stress during the test. And their blood samples showed that all the stress had managed to cause harmful changes to their immune system.

     "Loneliness has been thought of in many ways as a chronic stressor（慢性增压器） — a socially painful situation that can last for quite a long time," explained Jaremka, who led the study.

    The number of people suffering from loneliness is increasing all over the world. However, solving the problem is easier said than done. It won't work to just "tell anyone to go out and find someone to love you", said Jaremka. "We need to create support networks."

    From the modern London Eye to the historic Tower of London, below are London's most visited tourist attractions. Many of London's top attractions are free, making them affordable places to learn about some culture. Whether you prefer history or modern art, you'll find it at one of these must-visit spots.

British Museum

    The world-famous British Museum exhibits the works of man from prehistoric to modern times, from around the world. The most interesting and exciting parts include the Rosetta Stone, the Parthenon sculptures (雕塑) and the mummies in the Ancient Egypt collection. Some exhibitions require tickets.

National Gallery

    The greatest and most beautiful building of Trafalgar Square, London's National Gallery is a vast space filled with Western European paintings from the 13th to the 19th centuries. In this impressive art gallery you can find works by masters such as Van Gogh, da Vinci, Botticelli, Constable, Renoir, Titian and Stubbs. Some exhibitions require tickets.

Tate Modern

    Sitting on the banks of the Thames is the Tate Modern, Britain's national museum of modern and contemporary (当代的) art. Its unique shape is due to it being a power station before. The gallery's restaurants offer wonderful views across the city. Some exhibitions require tickets.

Coca-Cola London Eye

    The Coca-Cola London Eye is a major feature of London's skyline. It has some of London's best views from its 32 capsules, each weighing 10 tonnes and holding up to 25 people. Climb aboard for a breathtaking experience, with an unforgettable view of more than 55 of London's most famous landmarks — all in just 30 minutes!

Madame Tussauds

    At Madame Tussauds, you'll come face-to-face with some of the world's most famous faces. From Shakespeare to Lady Gaga you'll meet influential figures from show business, sport, politics and even royalty. Strike a pose with Usain Bolt, get close to One Direction or receive a once-in-a-lifetime audience with Her Majesty the Queen.

    Sometimes you'll hear people say that you can't love others until you love yourself. Sometimes you'll hear people say that you can't expect someone else to love you until you love yourself. Either way, you've got to love yourself first and this can be tricky. Sure we all know that we're the apple of our parents' eyes, and that our Grandmas think we're great talents and our Uncle Roberts think that we will go to the Olympics. But sometimes it's a lot harder to think such nice thoughts about ourselves. If you find that believing in yourself is a challenge. It is time you build a positive self-image and learn to love yourself.

    Self-image is your own mind's picture of yourself. This image includes the way you look, the way you act, the way you talk and the way you think. Interestingly, our self-images are often quite different from the images others hold about us. Unfortunately, most of these images are more negative than they should be. Thus changing the way you think about yourself is the key to changing your self-image and your whole world.

    The best way to defeat a passive self-image is to step back and decide to stress your successes. That is, make a list if you need to, but write down all of the great things you do every day. Don't allow doubts to occur in it.

    It very well might be that you are experiencing a negative self-image because you can't move past one flaw or weakness that you see about yourself. Well, roll up your sleeves and make a change of it as your primary task. If you think you're silly because you aren't good at math, find a tutor. If you think you're weak because you can't run a mile, get to the track and practice. If you think you're dull because you don't wear the latest trends, buy a few new clothes. But remember, just because you think it doesn't mean it's true.

    The best way to get rid of a negative self-image is to realize that your image is far from objective, and to actively convince yourself of your positive qualities. Changing the way you think and working on those you need to improve will go a long way towards promoting a positive self-image. When you can pat(拍) yourself on the back, you'll know you're well on your way. Good luck!

    While the start of a new school year is always exciting, this year was even more so for some elementary school students in Auckland, New Zealand. They became the world's first kids to be" taught" by a digital teacher, Will. Will is just an avatar(用户头像)that appears on the student's desktop, tablet, or smartphone screen, not a human-like robot walking around the classroom.

    Auckland energy company Vector and AI company Soul Machines worked together to develop Will, which has been modeled after the human brain and nervous system, allowing it to perform human-like behavior. The digital teacher is currently assigned to teach Vector's" Be sustainable with energy, "a free program for Auckland elementary schools.

    Just like the humans it replaced, Will is able to instantly react to the students' responses to the topic. Thanks to a webcam(网络摄像头)and microphone, the avatar not only responds to questions the kids may have, but also picks up non-verbal cues(非口头提示).For instance, if a student smiles at Will, he responds by smiling back. This two-way interaction not only helps capture the students' attention, but also allows the program's developers to monitor their engagement, and make changes if needed.

    Vector's Chief Digital Officer, Nikhil Ravishankar says," What was fascinating to me was the reaction of the children to Will. The way they look at the world is so creative and different, and Will really captured their attention."

    Will, in place since August 2018,has been a great success thus far. However, regardless of how popular it becomes, Will is unlikely to replace human educators any time soon .For one, the avatar's knowledge base is severely restricted. But more importantly, even the smartest digital avatars could never predict and react to all the unexpected situations that educators have to deal with on a daily basis. However, it could come in handy as a" personal tutor", providing kids with one-on-one help on specific subjects or even topics.

    The national environmental watchdog has declared that boosting efforts to cut air pollution in northern China, especially winter smog from the burning of coal, is a mission for this year.

    Burning coal for winter heating has been listed as one of the primary causes of air pollution, Chen Jining, minister of environmental protection, said on Monday at the annual meeting on environmental protection in Beijing.“As much as 60 percent of smog content is caused by coal burning in the starting phase of each smog”, said Fang Li, an official with Beijing's Environmental Protection Bureau. Therefore, Beijing has declared that it will wipe out coal use in its most rural areas by 2020.

    To start with, Beijing will replace coal-fired heating stoves with those powered by electricity or gas in 400 villages this year, before taking the campaign to the districts of Chaoyang, Haidian, Fengtai and Shijingshan by 2017,said Guo Zihua, a municipal rural development official. Beijing's downtown districts of Dongcheng and Xicheng eliminated coal burning last year, officials said.

    The capital and other places in northern China experienced several smog alerts in November and December, when peak readings were many times higher than the national safety level. Obviously, the situation is deteriorating, and will become a norm. So the government came up with a “smog subsidy (津贴)” for those who work outdoors, and 95 percent of the respondents to a survey support it.

    The Trade Union in Zhengzhou City surveyed subscribers to its official WeChat account and found that 88 percent of nearly 400 respondents said priority should be given to outdoor workers on smoggy days But 9 percent said air pollution affects everyone so it would be unfair to only address the concerns of people who work outdoors.

    Over half of the respondents think the extra subsidy, if applied, could come in the form of protective tools or cash. Twenty-two percent said money is the easiest way. To finance the proposed subsidy, 53 percent think the government and companies should jointly pay the bill, while 44 percent said central and regional governments should be responsible.

    Five thousand square meters of old damaged cars, motorcycles and boats fill this junkyard. For a casual onlooker, this might be a very sad sight. But for Andy, it's a real treasure. “I've been a junk hoarder(囤积者)for my whole life and I like fixing up what shouldn't be thrown away. Around 200 old cars end up in this junkyard every week. Some of them are sold for parts, others get repaired, and still others are beyond repair.”

    His father Bobby started the business some 50 years ago and still spends every morning there. The father and son have very different approaches to their work. They got a Dean cab that was getting thrown away and that was the father's project, which Andy did not want him to do.“ He did basically the opposite of everything I told him and I think he did it just to make me mad. He dumped a ton of money into this car, but in the end it wouldn't run.” Andy said jokingly.

    The unusual family business attracted the attention of a TV crew. That's how the show Janka Empire came to be featured on a network of the Discovery Channel. This show, five years of shooting, five seasons and 60 episodes(集), is popular. “There are hundreds of junkyards throughout the United States. I think what's interesting is that it is a family business. My father and I started the business and we joke very well back and forth and I think that's what people like. The cars that end up at the junkyard come out with endless surprises. See, this was a junk car and we restored it with a blown motor. Yet I don't get a chance to ride around it too often. Because despite its shining appearance, the noise of the engine is truly deafening and I worry my neighbors will not put up with it.”