Body language is an important part of communication(交流). If you want to communicate well, it's important to understand how you can (and can't) use your body to say what you mean, especially when you're in a foreign country. If a person is bored, he won't look at the person who is talking to him. He will find other things to do. He may also keep looking at his watch or a clock. If a person is open to you, his arms and legs will not be crossed. And if a person is relaxed, you will know it by looking at his body, even his breathing is slower.

Here are some examples of body language:

    A year ago, I paid no attention to English idioms, though my teacher emphasized the importance again and again. But soon, the importance of English idioms was shown in an amusing experience.

    One day, I happened to meet an Englishman on the road, and soon we began to talk. As I was talking about how I was studying English, the foreigner seemed to be astonished gently shaking his head, shrugging his shoulders, saying, “You don't say!” “You don't say!” I was puzzled. I thought, perhaps this is not an appropriate topic. “Well, I'd better change the topic.” So I said to him, “Well, shall we talk about the Great Wall By the way, have you ever been there. “Certainly, everyone back home will laugh at me if I leave China without seeing it. It is magnificent.” He was deep in thought when I began to talk like a tourist guide, “The Great Wall is one of the wonders in the world. We are very proud of it.” Soon I was interrupted again by his order, “You don't say!” I couldn't help asking. I said, “Didn't you say you don't say” Hearing this, the Englishman laughed to tears. He began to explain, “You don't say actually means really It is an expression of surprise. Perhaps you don't pay attention to English idioms.” Only then did I realize I had made a fool of myself. Since then, I have been more careful with idiomatic expressions.

    Their cheery song brightens many a winter's day. But robins are in danger of wearing themselves out by singing too much. Robins are singing all night一as well as during the day, British-based researchers say.

    David Dominoni, of Glasgow University, said that light from street lamps, takeaway signs and homes is affecting the birds' biological clocks, leading to them being wide awake when they should be asleep.

    Dr Dominoni, who is putting cameras inside nesting boxes to track sleeping patterns, said lack of sleep could put the birds' health at risk. His study shows that when robins are exposed to light at night in the lab, it leads to some genes being active at the wrong time of day. And the more birds are exposed to light, the more active they are at night.

    He told people at a conference, "There have been a couple of studies suggesting they are increasing their song output at night and during the day they are still singing. Singing is a costly behaviour and it takes energy. So by increasing their song output, there might be some costs of energy."

    And it is not just robins that are being kept awake by artificial light. Blackbirds and seagulls are also being more nocturnal. Dr Dominoni said, "In Glasgow where I live, gulls are a serious problem. I have people coming to me saying `You are the bird expert. Can you help us kill these gulls?'.During the breeding(繁殖)season, between April and June, they are very active at night and very noisy and people can't sleep."

    Although Dr Dominoni has only studied light pollution, other research concluded that robins living in noisy cities have started to sing at night to make themselves heard over loud noise.

    However, some birds thrive(兴旺)in noisy environments. A study from California Polytechnic University found more hummingbirds in areas with heavy industrial machinery. It is thought that they are capitalising on their predators(天敌)fleeing to quieter areas.

    Are people less happy or more happy the older they get? A study found that people generally become happier and experience less worry after age 50. In fact, it found that by the age of 85, people are happier with their life than they were at 18.

    The finding came from a Gallup survey of more than 340,000 adults between the age of 18 and 85 in the United States.

    Arthur Stone in the Department of Psychiatry and Behavioral Science at Stony Brook University in New York led the study. His team found that levels of stress were highest among adults between the ages of 22 and 25. Stress levels dropped sharply after people reached their fifties.

    Happiness was highest among the youngest adults and those in their early seventies. But the people least likely to report feeling negative emotions were those in their seventies and eighties. The survey also found that men and women had similar emotional patterns as they grow older. However, women at all ages reported more sadness, stress and worry than men did.

    The researchers also considered possible influences like having young children, being unemployed or being single. But they found that influences like these did not affect the levels of happiness and well-being related to age.

    So why would happiness increase with age? One theory is that, as people get older, they become more thankful for what they have and have better control of their emotions. They also spend less time thinking about bad experiences.

    The original goal of the study was to confirm the popular belief that aging is connected with increased sleep problems. The survey did find an increase during middle age, especially in women. But except for that, people reported that they felt their sleep quality improved as they got older.

    You can use your smartphone to get pretty much anything delivered directly to your door almost immediately. The hardest part is the process of trying to work out if you should tip and if so, doing the quick math before you get to the door. And, you know well that you should tip about 15-20% at restaurants, but do the same rules apply to delivery drivers?

    The co-founder of Grubhub, Matt Maloney, pretty much set the standard for tipping delivery people in a Facebook post. He's a strong supporter of tipping, and Grubhub's website suggests a $5 or a 20% tip. Maloney also said this number should go up if you order during, say, a snowstorm.

    However, most other delivery services say on their websites that tipping is not required. Some services, like Door Dash, do suggest no tip on their checkout window. Many, like Amazon Prime Now, allow customers to change their tip amount after their delivery has been received to reflect the quality of service. These companies help customers save money but delivery drivers are upset. They deal with bad weather, heavy traffic, extreme tiredness, and more, all for a $1 tip. Many feel that if you'd tip your pizza boy or girl, you should tip your delivery driver.

    The Emily Post Institute (EPI)'s official suggestion falls in line with Maloney's: “10-15% of the bill, or $2-5 for pizza delivery depending on the size of the order and difficulty of delivery.”

    Just like servers in a restaurant, delivery drivers almost always rely on your tips for their income. Tipping is a long-standing cultural tradition in America. So, until drones (无人机) can deliver hot dogs straight to your door, it's best to tip the people riding through the city at all hours to bring you hot fresh food.

    The World Health Organization recently said that it planned to add gaming disorder (游戏成瘾) to its new list of disease classifications, angering the gaming industry but pleasing doctors who hope it may make treatment more easily available.

    Some US experts said it would make little difference when it comes to helping people with the disorder, although others said it would bring attention to a disorder that people sometimes don't recognize. So some experts disagree WHO's plan.

    Many of us enjoy video games, but does playing our favorite game for a couple of hours every night mean we're suffering from gaming disorder? Not according to the WHO.

    The symptoms listed by the WHO include a lack of control over gaming, treating gaming more seriously than other life interests and daily activities, and continuing to play games despite the negative consequences that playing them might have.

    "The behavior pattern is enough to result in significant damage to one's personal, family, or social life." the WHO said.

    Meanwhile, Douglas Gentile of Iowa State University has carried out influential research into the cause of gaming addiction in young people." I and many others had assumed that gaming is not really a problem but is a symptom of other problems," he told NBC News. Many had thought it was simply a failure of self-control. To see if it was, Gentile's team studied a group of children who had been gaming for several years." We found that when kids became addicted, their anxiety increased … and their grades decreased," Gentile said. When kids were able to back off from gaming, their symptoms disappeared, he added.

    Gentile thinks medical organizations should pay attention to the WHO's proposal." This isn't an issue of opinion; it's an issue of science," he said." This is a major scientific and medical organization. They don't do things lightly and without reason."

    Dr Petros Levounis, chair of psychiatry at the New Jersey Medical School at Rutgers University, said that he hoped the WHO's proposal would lead to more research into obsessive (过度的) behavior among all types of people.

    "Now, there is renewed interest and excitement," he said. So some experts are in favour of WHO's plan.