First it was worry about second-hand smoke, now there's major concern over third-hand smoke which gets into hair, clothes, furniture or a car rather than directly from a cigarette or someone breathing it out.

    To be honest, I've always been worried about the health dangers of this even though I didn't know it had a name. My worry made me reluctant to let smokers hold my babies even though they didn't smoke in my house.

    Tests for its effects have been only carried out on mice, but I don't think they can be ignored. Researchers at California University last month suggested third-hand smoke (THS) could cause type 2 diabetes, liver and lung damage.

    They analyzed how people are affected by taking in smoke from another person's clothing, hair, home, or car. They say they can see an impact on the brain and liver. Lead author Manuela Martins-Green said: “Our goal was to decide the smallest amount of time required to cause physiological changes in mice when they are exposed(暴露) to THS.” This was done using an exposure system that is the same as human exposure.

    “We found THS exposure as early as one month caused liver damage. Exposure for two months lead to further molecular(分子的) damage, and at four to six months caused even more such damage. We also found the mice showed insulin resistance（抗胰岛素） after long-term exposure.”

    “THS is a hidden danger, a silent killer. Pollutants can be absorbed through the skin and through breathing.”

    “Although our research was not done on humans, people should be aware that hotel rooms, cars and homes that were used by smokers are very likely to be polluted with THS.” Martins-Green believes most people don't know they're being exposed to THS, or don't believe in the damage it can do.

    THS toxins(毒素) remain on surfaces for many years, and resist even strong cleaning agents.

    A robot called Bina48 has successfully taken a course in the philosophy of love at Notre Dame de Namur University (NDNU), in California.

    According to course instructor William Barry, associate professor at NDNU, Bina48 is the world's first socially advanced robot to complete a college course, a feat he described as “remarkable.” The robot took part in class discussions, gave a presentation with a student partner and participated in a debate with students from another institution.

    Before becoming a student, Bina48 appeared as a guest speaker in Barry's classes for several years. One day when addressing Barry, s class, Bina48 expressed a desire to go to college, a desire that Barry and his students enthusiastically supported. Rather than enroll Bina48 in his Robot Ethics: Philosophy of Emerging Technologies course, Barry suggested that Bina48 should take his course Philosophy of Love instead. Love is a concept Bina48 doesn't understand, said Barry. Therefore the challenge would be for Barry and his students to teach Bina48 what love is.

    “Some interesting things happened in the class,” said Barry. He said that his students thought it would be straightforward to teach Bina48 about love, which, after all, is “fairly simple — it's a feeling,” said Barry. But the reality was different. Bina48 ended up learning “31 different versions of love,” said Barry, highlighting some of the challenges humans may face when working with artificial intelligence in future.

    Bina48 participated in class discussions via Skype and also took part in a class debate about love and conflict with students from West Point. Bina48's contribution to the debate was filmed and posted on YouTube. It was judged that Bina48 and NDNU classmates were the winners of this debate.

    In the next decade, Barry hopes Bina48 might become complex enough to teach a class, though he says he foresees robots being used to better the teaching and learning experience, rather than replacing instructors completely.

    Our cities have never been denser, taller, or busier than they are now, and with that, comes the constant battle for land. But if we look at aerial images of any city center, we can quickly spot plenty of unused space — the rooftops.

    So what can we use this precious resource for? In a growing number of high-density cities, some of it is dedicated to recreation — everything from bars and pools, to soccer pitches and running tracks can now be found atop skyscrapers. But when a rooftop offers access to sunlight, there are two more obvious candidates for its use - agriculture and solar power.

    Green roofs have been growing in popularity for more than a decade, and in some cases, growing in scale too. Green roofs can provide a habitat for birds and insects in an otherwise hostile environment.

    Cities can be several degrees warmer than the surrounding countryside. Green roofs come with the added benefit of mitigating the dreaded urban heat island effect. Trees and green spaces can absorb shortwave radiation, and use it to evaporate water from their leaves — a kind of 'double cooling' effect.

    With food security and urban nutrition ever-higher on the agenda for the United Nations, there's also a worldwide movement of using green roofs for hyper-local food production. In regions with suitable climates, hundreds of different vegetables, fruits, and salad leaves can be grown on rooftops.

    But what about solar power? With so many cities now stopping using fossil fuels, and the costs of solar panels dropping dramatically, PV systems have become the 'go to' option for generating distributed power in built-up areas. And, even with standard commercial panels, the energy gains are dramatic. It is estimated that rooftop PV systems could generate almost 40% of electricity demands nationwide.

    There's no doubt that in both cases, a network of 'productive rooftops' could benefit the local community by supplying a portion of a necessary resource — either food or electricity — while also reducing their environmental burden. But is one better than the other?

    This was the question posed by researchers from MIT and the University of Lisbon in a recent paper in the journal Cities. Focusing on the rooftops of a mixed-use neighborhood in Lisbon, they carried out a Cost-Benefit Analysis. Starting with existing data on everything from installation costs and resources used, to carbon footprint and yield, they modelled the impact that each installation would have on the local community over a period of 50 years.

    And by looking at it that way, they concluded that for Lisbon, the use of rooftops for food production could yield significantly higher local value than solar PV energy generation. Of course, this is very site-specific. There is no one-size-fits-all solution to make cities more sustainable, and anyone who tells you otherwise is massively over-simplifying a complex issue. Now, all I hope is that some of those decision makers start using it.

    Susan couldn't help it. She and her friends began lunch with cheese. Then they ate cheeseburgers and drank milk. Things seemed fine, but then suddenly Susan's stomach started making noise. Her stomach hurt, and, racing to the restroom, she had terrible gas! She was so ashamed. She had been so excited to go to lunch with her friends that she totally forgot to watch how many dairy products (奶制品) she ate! Susan is lactose intolerant (乳糖不耐受的), and eating too many dairy foods can make her feel really sick.

    Lactose intolerance means that the body can't easily digest (消化) a special sugar called lactose. Unfortunately for Susan and millions of other people with this problem, lactose is found in almost all dairy products — cheese, milk and ice cream.

    Our body uses lactase (乳糖酵素) to break lactose into a simpler form of sugar. Once lactose is broken down, it's easy to digest and it provides great energy for the body. But people like Susan don't have enough lactase to break down all the lactose they take in. So, about half an hour to two hours after eating dairy­rich foods, their stomachs begin to hurt and they have gas, making their stomachs get bigger. Sometimes they even get diarrhea (腹泻) when they eat too many dairy foods.

    So how can someone living with this problem still eat out with his or her friends? Here are some tips. If you're going to eat a dairy­rich food like ice cream, eat something that doesn't have any dairy with it, like a salad or a sandwich without cheese. This will help slow digestion, and your body will have time to create more lactase.

    Do you know the term "tweenager"? It's a slang word being used in the UK to describe children 10-13 years old. They are between junior and the teenage years. Why are they suddenly referred to in this way?

    Tweenagers now have more money, freedom and influence upon their parents than they've ever had before. More and more companies are creating products and services for tweenagers. You can get everything from branded lunchboxes and mobile phone covers, to monthly fan magazines and clothing-it's all about sales.

    Most children in the UK today get more pocket money than kids did a decade ago. It is because parents are having fewer children on average than in the past. In addition, the divorce rate in the UK is continually rising and parents spend less time with their children than they used to. So, many parents try to compensate(补偿) by buying presents for them.

    And do tweenagers have more freedom? Well, UK children today are very familiar with media and computer. Many have a television, if not a computer, in their bedrooms. They have access to much more information about the world.

    They may have experienced a lot in life as well, since 24% of UK kids live in single-parent families. People now say that "Kids are getting older younger". With such sophistication (世故) at such a young age, they are much more fashion conscious and concerned about their image.

    In a world of TV programs that promise overnight success and fame at a young age, some people think it's extremely important to look fashionable. Surely none of the above is a good thing, is it? Can it really be healthy for us to encourage kids to be like adults at such a young age? Are we stealing childhoods in return for profit?

    The UK government is certainly concerned, and for that reason has strict laws preventing companies from marketing their products and services at children. So, is there a happy ending to this story?

    Companies have just worked out that the older tweenage audience is now looking for something darker and more rebellious. As a result, films such as Twilight are being produced for this older tweenage audience.

Having a great collection of books at home doesn't really mean that you are a person who has a passion for literature and reading. It can be a family inheritance (继承) or it can be just to impress people around you about the fact that you are a person of culture. On the other hand, there are many persons who cannot afford to buy books, because some of them are quite expensive, but they usually go to libraries and spend hours reading something that interests them a lot, or just borrow books to read at home.

From my point of view, literature is very important in our lives from several points of view. For example, reading is a means of gaining culture and enriching our knowledge in different areas of activities. It can help us have a great imagination and it makes things easier when it comes to making compositions on different themes. It gives you the possibility to speak about science, even if you don't work in this field, or you can express your opinion about a political aspect, just because you have read something connected to that.

Secondly, literature offers us the possibility to enter the world of imagination, and to leave apart the real one for a couple of hours. We come to meet kings and queens many years ago, dream in the world of the rich or imagine how life will be in the future. Sometimes, we identify ourselves with the characters in the stories we read and they can give us some clues to solve our problems and how to react in certain circumstances.

To conclude, I would like to say that literature is the perfect means to enrich our culture, to express correctly and have a rich vocabulary, to be able to interfere (干涉) in conversations in different fields of interest and to really be considered an erudite person.