The oddness of life in space never quite goes away. Here are some examples.

    First consider something as simple as sleep. Its position presents its own challenges. The main question is whether you want your arms inside or outside the sleeping bag. If you leave your arms out, they float free in zero gravity, often giving a sleeping astronaut the look of a funny balled （芭蕾）dancer. “I'm an inside guy,” Mike Hopkins says, who returned from a six-month tour on the International Space Station. “I like to be wrapped up.”

    On the station, the ordinary becomes strange. The exercise bike for the American astronauts has no handlebars. It also has no seat. With no gravity, it's just as easy to pedal violently. You can watch a movie while you pedal by floating a microcomputer anywhere you want. But station residents have to be careful about staying in one place too long. Without gravity to help circulate air, the carbon dioxide you exhale (呼气) has a tendency to form an invisible （隐形的）cloud around you head. You can end up with what astronauts call a carbon-dioxide headache.

    Leroy Chiao, 54, an American retired astronaut after four flights, describes what happens even before you float out of your seat,”Your inner ear thinks your're falling . Meanwhile your eyes are telling you you're standing straight. That can be annoying—that's why some people feel sick.” Within a couple days —truly terrible days for some —astronauts' brains learn to ignore the panicky signals from the inner ear, and space sickness disappears.

    Space travel can be so delightful but at the same time invisibly dangerous. For instance, astronauts lose bone mass. That's why exercise is considered so vital that National Aeronautics and Space Administration (NASA) puts it right on the workday schedule. The focus on fitness is as much about science and the future as it is about keeping any individual astronauts return home, and, more importantly, how to maintain strength and fitness for the two and a half years or more that it would take to make a round-trip to Mars.

    When Mark Levine, an English-language instructor at Beijing's Minzu University of China, was first invited to attend a Chinese colleague's wedding in Jiangsu Province in 2016, his second year in China, the California native was ready to present a small decorative gift for the new couple as he used to do in the United States.

    However, his gesture suddenly seemed inappropriate as he realized the Chinese at the ceremony had red envelopes filled with cash to present rather than a packed gift.

    "It's a little bit embarrassing when you present something that people didn't expect to receive on certain occasions," Levine told China Daily recently. "In the US, people do that as well but only for close relatives. People would normally give things as presents, while here in China red envelopes are more commonly welcomed."

    It was the first time that the 66-year-old had discovered the Chinese rules in gift giving. He was not alone.

    British Minister of State for Transport Baroness Susan Kramer presented a watch in January to Ko Wen-je, mayor of Taipei, when she visited the city, immediately sparking headlines as she broke a long-held tradition in Chinese culture.

    A clock or watch, or zhong in Mandarin, represents "the end" in Chinese, and many associate it with death. Therefore, giving someone, especially an elder, a clock or watch implies "your time is up".

    Kramer later apologized for the mistake, but Ko also came under fire for his response as he told reporters that he had no use for the watch and would sell it for cash.

    However, some foreigners in China stand by Ko in this particular debate, such as Mark Dreyer, a British citizen who has lived and worked in China since 2007."After all, 'don't give clocks or watches to your hosts' is on page l of most China travel guides. I'm embarrassed by the lack of respect shown by the British for not even reading about the customs beforehand."

    Every city, in fact, can be felt by its warmth-not in terms of its natural climate but its human touch.

    About twenty years ago, I arrived in Australia. Searching for a place in a map in the street, I was approached by an elderly man who asked “How are you? Are you lost? How can I help you?”, which really impressed and warmed me. Another time, as I was pushing my bike on the sidewalk one night, a young lady shouted to me: “Carry me please” and then jumped onto my bicycle. While we had a little chat, she got where she wanted and hopped off my bike with “Thanks, bye!” At that moment, I had a sense as much of pleasant surprise as of “being trusted”.

    Still in Australia, two of my friends decided to hitch（搭便车）their way to Sydney in order to save money. A young driver stopped, and luckily he was also going to Sydney, so he let them in and even allowed them to drive while he went to sleep on the back seat. About eight hours later, they arrived and he woke up. Saying thanks to each other, they went their separate ways.

    In my opinion, no matter how developed and advanced it is, if in general a place presents itself with a cold and indifferent（冷漠的）face to people, especially to strangers, even keeping them highly alert（警惕的）not to be cheated all the time, can perhaps hardly be classified as a land of civilization（文明）. In a sense, the attitude towards strangers that the people have in the city mirrors its warmth.

    Chinese people are, quite rightly, proud of their food. However, when foreigners like Britons and Americans think of Chinese food, their impression of it is different to what you might think.

    Growing up in the UK, the Chinese food I was used to eating was food I now recognize as being from Guangdong. For example, a typical dish I would order would be pork in sweet and sour sauce, probably with some rice and spring rolls on the side. This is the type of food we generally eat because most Chinese immigrants(移民) to the UK have come from Guangdong. You can tell, because when most British people try to copy the sound of Chinese, they actually copy the sound of Guangdong people—hearing the real Putonghua is sometimes a shock to British people who have grown up thinking it sounds completely different!

    British attitudes to Chinese food may be changing, though. Chinese-American chef Ken Hom has been on British TV for 30 years, and he told BBC Food: "Chinese food at the beginning of the 80s (in the UK) was sweet and sour pork, mainly. Most Brits had the unchangeable view of Chinese food… Now you are seeing more local Chinese food from Sichuan, Hunan and other areas of China. It is no longer just Guangdong food." Similarly, to most Americans, Chinese food doesn't go too far past orange chicken and fortune cookies, but more Chinese local dishes are becoming successful, especially in big cities like New York.

    Attitudes have not quite changed completely, though. Many foreigners who live in China will be familiar with this question from a relative back at home: "Have they given you dog yet?" Yes, perhaps because people still know too little about Chinese culture, many people believe that Chinese people love to eat dog meat. And of course, some people do eat dogs, which to Americans is like "eating a member of one's family" according to Vision Times. Also, Chinese people eat many other things people in the West do not—chicken claws, duck heads and some animals' organs.

    But what do foreigners think when they come to China and taste real Chinese food? You'll be glad to know that in my experience, the impressions have been very good.

    Why is pink or purple a color for girls and blue or brown for boys?

    The answer depends largely on cultural values as well as personal experiences. To the Egyptians, green was a color that represented the hope and joy of spring, while for Muslims, it means heaven. Red is a symbol of good luck in many cultures. In China, children are given money in a red envelope to bring good fortune in the New Year. For many nations, blue is a symbol of protection and religious beliefs. Greek people often wear a blue necklace hoping to protect themselves against evils(灾祸).

    People's choice of colors is also influenced by their bodies' reactions toward them. Green is said to be the most restful color. It has the ability to reduce pain and relax people both mentally and physically. People who work in green environments have been found to have fewer stomachaches.

    Red can cause a person's blood pressure to rise and increase people's appetites(食欲). Many decorators will include different shades of red in the restaurant. Similarly, many commercial websites will have a red “Buy Now” button because red is a color that easily catches a person's eye.

    Blue is another calming color. Unlike red, blue can cause people to lose appetite. So if you want to eat less, some suggest that eating from blue plates can help.

    The next time you are deciding on what to wear or what color to decorate your room, think about the color carefully.

    A Japanese telecom company has designed a robot that it says has emotions (情绪). But rather than run in fear from it, we've welcomed it into our homes: Pepper, the "emotional robots" sold out within a minute of going on sale.

    Created by Aldebaran Robotics and Japanese mobile giant SoftBaok, Pepper went on sale to the general public in Japan on June 20. It is "the first humanoid (类人的) robot designed to live with humans, " Aldebaran says on its website. Pepper costs about $ 1, 600. And like all good mobile products, there's a $ 120 per month data fee, as well as an $80 per month damage insurance fee. According to a news report, Pepper can pick up on human emotions and create his own using a "multi - layer neural (神经的) network." Pepper's touch sensors and cameras are said to influence its mood, which is displayed on the tablet-sized screen on its chest.

    Pepper will sigh when unhappy, and can go around your house recording your family's daily activity. Aldebaran says Pepper can feel "joy, surprise, anger, doubt and sadness," but it doesn't say how strongly it can feel these emotions. What happens when Pepper is having a bad day? Will it, like many humans, become uncooperative? Will it ask for some time alone? What happens if it knows that its purpose in life is just to take part in small talk? Thankfully, Pepper is only about four feet tall, with roller balls instead of legs, so if it is angry with and even turns on its owners, you'll be safe if you can make it upstairs.

    Aldebaran says in reality, they're probably quite a few years away from artificial intelligence that could create real emotions. Aldebaran wasn't immediately able to tell when Pepper will be available out of Japan, but additional sales are scheduled for July after the first 1, 000 units sell out. SoftBank currently uses the robots in its stores as greeters, and it plans to offer Pepper to other stores in the future. Hopefully "boredom" is not an emotion Pepper can feel.