It could happen just about any time you step out in public. You get onto an almost-empty bus, but the next passenger in decides to ignore dozens of empty seats to sit right next to you. While you're waiting in line at a supermarket, the next customer insists on standing only two inches behind you and shouting into his cell-phone. You go into a public restroom, and the next person to enter decides to use the next stall. Transgressions(冒犯) like these don't just make us feel uncomfortable; we often feel anxious, alarmed; and violated(被侵犯的). It is the attack of the personal-space invaders.

    In any society, shared definitions of personal space govern how we interact with other people. People living in densely(密集地) populated cities like Mumbai, Beijing, or Mexico City tend to require less personal space than people living in sparsely(稀少地) populated places within the country. In America, New Yorkers often have smaller requirements than residents of western states, like Montana, Shenandoah and Wyoming. Because everyone has different standards, gestures that are innocent in one place can be interpreted as opposite in another, especially in Britain.

    As the British etiquette(礼仪) website Debrett puts it, as a British person, somebody standing too close may make you "focus less on what somebody is saying than on how close they are to you". Simple acts like putting an arm around someone you don't know may seem friendly in China, but they can make us very uncomfortable. People from many European countries such as France and Spain kiss each other on the cheek when they meet, yet to British person, this seems too friendly and "touch-freely". The website explains! "The British are not backslappers(拍人后背的人) and generally do not show affection in public".

    Are British people unfriendly? Far from it. The website adds that they are not as "stand-offish and aloof' as they may seem, but very friendly and helpful to foreigners. However, remember not to be too close. If you are going to come closer than an arm's length, please let them know.

    The Asian elephant has been respected for centuries and is still used today for ceremonies and religious purposes. It is respected, not only because it plays a role in Asian culture and religion, but also because it is a key biological species in the tropical forests of Asia.

    The Asian elephant is the largest land mammal in Asian. It is smaller than the African elephant, with relatively smaller ears. Asian elephants have a single “finger” on the upper lip of the long trunk, while African elephants have a second on the lower tip. A number of adult male Asian elephants have no tooth, and the percentage of males carrying ivory(象牙）is different from only about 5% in Sri Lanka to 90% in south India. Asian elephants keep their ears in constant motion in order to free the heat they produce. The species is reported to have well-developed hearing, vision, and smell , and they are also fine swimmers.

    Asian elephants prefer to convey something to form groups surrounding 6 to 7 related females that are led by the oldest female. Like African elephants, these groups occasionally join others to form herds, although these associations are relatively temporary.

    More than two thirds of the day may be spent feeding on grasses, but large amounts of tree bark, roots, leaves and small stems are also eaten. Crops such as bananas, rice and sugar plants are favored foods. Besides, they need to drink at least twice a day so the source of water is quite important.

    The Asian elephant used to live from modern Irap and Syria to the Yellow River in China at first, but it is now found only from India to Vietnam, with a tiny population in the extreme southwest of China's Yunnan Province. More than 100,000 Asian elephants may have existed at the start of the 20^th century. The population is estimated to have fallen by at least 50% over the last 60-75 years.

    A young woman sits alone in café sipping tea and reading a book. She pauses briefly to write in a nearby notepad before showing her words to a passing café waiter: “Where are the toilets please?” This is a familiar scene in Tokyo's so-called “silent cafes”, where customers are not allowed to speak, and only communicate by writing in notepads.

    The concept rises by a desire to be alone among young Japanese, a situation brought by economic uncertainly, a shift in traditional family support structures and the growing social isolation. The phenomenon is not limited to coffee shops but covers everything from silent discos, where participants dance alone wearing wireless headphones connected to the DJ, to products such as small desk tents designed for conversation-free privacy in the office. One Kyoto company even offers single women the opportunity to have a “one woman wedding” – a full bridal affair, complete with white dress and ceremony, and the only thing missing is the groom. The trend has its own media expression – “botchi-zoku”, referring to individuals who consciously choose to do things completely on their own.

    One recent weekday afternoon, Chihiro Higashikokubaru, a 23-year-old nurse, travelled 90 minutes from her home, to Tokyo on her day off in order to enjoy some solo time. Speaking quietly at the entrance of the café, Miss Higashikokubaru said: “I heard about this place via Twitter and I like the idea of coming here. I work as a nurse and it's always very busy. There are very few quiet places in Tokyo, and it's a big busy city. I just want to come and sit somewhere quietly on my own. I'm going to drink a cup of tea and maybe do some drawings. I like the idea of a quiet, calm atmosphere.”

    The desire to be isolated is not a new concept in Japan, home to an estimated 3.6 million “hikikomori” – a more extreme example of social recluses（隐士）who withdraw completely from society.

    About ten men in every hundred suffer from color blindness in some way. Women are luckier; only about one in two hundred is affected in this matter. Perhaps, after all, it is safer to be driven by a woman!

    There are different forms of color blindness. In some cases a man may not be able to see deep red. He may think that red, orange and yellow are all shadows of green. Sometimes a person cannot tell the difference between blue and green. In rare cases an unlucky man may see everything in shades of green — a strange world indeed.

    Color blindness in human beings is a strange thing to explain. In a single eye there are millions of very small things called "cones". These help us to see in a bright light and to tell difference between colors. There are also millions of "rods", but these are used for seeing when it is near dark. They show us shape but no color.

    Some insects have favorite colors. Mosquitoes prefer blue to yellow. A red light will not attract insects, but a blue lamp will. In a similar way human beings also have favorite colors. Yet we are lucky. With the aid of the cones in our eyes we can see many beautiful colors by day, and with the aid of the rods we can see shapes at night. One day we may even learn more about the invisible colors around us.

    Today, we are constantly bombarded with media reports about research on the right diet to follow to help us maintain a healthy lifestyle or lose weight—but it's hard to know which one to pick and, once chosen, it's harder still to stick to it. And now there's another choice to get our teeth into.

    A flexitarian(弹性素食者)diet involves eating plant—based foods and only occasionally eating meat and fish. This eating style allows you to supplement some ingredients that you wouldn't get in a stricter vegan(素食主义者)diet—another trend growing in popularity. And like veganism, flexitarianism isn't about eating carefully to help you lose a few pounds—it's something people choose for ethical reasons, to help the planet. And a study into the global food system and how it affects the climate, has found that eating mainly plant-based foods is one of three key steps towards a sustainable future for all by 2050.

    This research found that food waste will need to be halved and farming practices will also have to improve to achieve this. But without a single solution, a combined approach is needed. Dr Marco Springmann from the University of Oxford was one of the lead authors of the report. He told the BBC “We really found that a combination of measures would be needed to stay within environmental limits and those include changes towards healthier more plant—based diets.”

    But whereas vegans think it's wrong for animals to be killed for food, flexitarians believe eating meat once in a while is acceptable. And Dr Springmann agrees—as long as we “treat it as a luxury, it's probably OK but you shouldn't have more than one serving of red meat, which includes beef and pork, per week.” And here's another fact to digest: If we moved to this type of diet, the study found that greenhouse gas emissions from agriculture would be cut by more than half.