Grammar is the system of a language. People sometimes describe grammar as the “rules” of a language; but in fact no language has rules. If we use the word “rules”, we suggest that somebody created the rules first and then spoke the language, like a new game. But languages did not start like that. Languages started by people making sounds which evolved (逐渐发展成) into words, phrases and sentences. No commonly-spoken language is fixed. All languages change over time. What we call “grammar” is simply a reflection (反映) of a language at a particular time.

    Do we need to study grammar to learn a language? The short answer is “no”. Very many people in the world speak their own, native language without having studied its grammar. Children start to speak before they even know the word“grammar”. But if you are serious about learning a foreign language, the long answer is “yes, grammar can help you to learn a language more quickly and more efficiently.” It's important to think of grammar as something that can help you, like a friend. When you understand the grammar (or system) of a language, you can understand many things yourself, without having to ask a teacher or look in a book.

So think of grammar as something good, something positive, something that you can use to find your way—like a signpost(路标) or a map.

    Except invented languages like Esperanto（世界语）. And if Esperanto were widely spoken, its rules would soon be very different.

    It is quite reasonable to blame traffic jams, the cost of gas and the great speed of modern life, but manners on the road are becoming horrible. Everybody knows that the nicest man would become fierce tigers behind the wheel. It is all right to have a tiger in a cage, but to have one in the driver's seat is another matter.

    Road politeness is not only good manners, but good sense. It takes the most cool-hearted drivers great patience to give up the desire to beat back when forced to face rude driving. On the other hand, a little politeness goes a long way towards reducing the possibility of quarrelling and fighting. A friendly nod or a wave, or thanks in answer to an act of politeness helps to create an atmosphere of good will and becomes so necessary in modern traffic conditions. But such behaviors of politeness are by no means enough. Many drivers nowadays don't even seem able to recognize politeness when they see it.

    However, misplaced politeness can also be dangerous. Typical example is the driver who waves to a child crossing the street at a wrong place into the path of oncoming cars that may not be able to stop in time. The same goes for encouraging old ladies to cross the road wherever and whenever they want to.

    An experienced driver, whose manners are faultless, told me it would help if drivers learnt to correctly join in traffic stream without causing total jams that give rise to unpleasant feelings. Unfortunately, modern drivers can't even learn to drive, let alone master the roadmanship(驾车技能). Years ago, experts warned us that the fast increase of the car ownership would demand more give-and-take from all road users. It is high time that all of us took this message to heart.

    A new report from the International Bar Association (IBA) suggests machines will mostly likely replace humans in a growing number of occupations. One of the authors of the report, Gerlind Wisskirchen, believes that governments need to introduce human quotas（配额）in some sectors in order to protect jobs.

    The report suggests that the jobs at risk are common ones, such as accountants and lawyers. Financial services are more at risk than legal roles though, as algorithms（计算机程序）are easier for a computer to solve when compared to keeping client relationships and making new laws. Simple physical work is also in the firing line, the authors mention.

    As the world population heads toward 7 to 10 billion, futurist Morris Miselowski says, “I am not sure that this nine-to-five, Monday to Friday work as we understand it, will continue for many of us for the next couple of decades.” He forecasts that the biggest changes will be a shift（转变）away from the traditional work time..

“Artificial intelligence (AI)（人工智能）… and all sorts of new technologies are just about to happen; all of that's going to change where, how and when we do work.”

Ms Wissfikirchen was surprised by how far-reaching the effects of automation（自动化）are.

     “Even though automation began 30 years ago in the blue-collar sector, the new development of artificial intelligence and robotics affects not just the blue-collar sector, but the white-collar sector,” said Ms Wisskirchen.

    Toby Walsh, professor of Artificial Intelligence at UNSW, said there was a ray of hope when it came to technology and the future of jobs.

“It's always good to remember that although technology will take jobs away as they raise in this report, there will also be new jobs created by technology,” he said. “In fact if we look at the history of technology since the Industrial Revolution, more jobs have been created than destroyed.”

    People who have seen Trisha Seifried Woodall with her cats say that she has a magic touch. Most people don't know anyone who can order a cat to jump on a table, sit for two minutes, and then jump to the floor and walk backward.

    Ms. Seifried Woodall has taught her cats to do all these tricks -- and many more. At her training center. Got Pet-ential, cats learn tricks for TV and magazine ads. Some of her cats have appeared on bags of cat food.

    When Ms. Seifried Woodall gets a cat, she first learns what that cat likes and doesn't like. "Some cats like to stay close to the ground, so I'll teach them how to stand behind me, and walk with me," she says. "Other cats, like high places, so they'll learn how to jump on my bent knee and then safely leap to my shoulder."

    Ms. Seifried Woodall grew up in a family with many pets, and she was first paid to work with animals when she was 18. At a summer job at an amusement park, she learned how to train a few of the animals for performances. She continued to train and learn about animals for 20 years before starting her own animal-training center.

    Ms. Seifried Woodall is proud of the skills her cats have learned, but she is also proud that her center's cats are healthy and social. She believes her cats enjoy learning new tricks.

    In Ms. Seifried Woodall's experience, no breed (品种) of cat is easier to train than others. All of her cats came from shelters. They have become pets in her home.

    Like most animal trainers, Ms. Seifried Woodall uses a reward system. Cats that are successful during training get food or a new toy. A cat that doesn't enjoy eating or playing will probably not be interested in being trained. She never scolds (责骂) them. "Cats need a lot of encouragement when they are performing, she says." I say good job or that s right several times during a single minute."

    The fiddler crab (蟹) is a living clock. It indicates the time of day by the colour of its skin, which is dark by day and pale by night. The crabs changing colour follows a regular twenty-four hour plan that exactly matches the daily rhythm (节奏) of the sun.

    Does the crab actually keep time, or does its skin simply answer to the sun's rays, changing colour according to the amount of light strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crab's skin colour continued to change exactly on time.

    This characteristic(特性) probably developed gradually in answer to the daily rising and setting of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely regulated (受控制) inside the living body of the crab.

    The biologists noticed that once each day the colour of the fiddler crab is especially dark, and that each day this happens fifty minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides (潮水). The crabs period of greatest darkening is exactly the time of low tide on the beach where it was cought!

Singapore researchers say they have developed a form of electronic skin that can create a sense of touch. They hope their invention will give people with prosthetic hands (假肢手) the ability to identify different objects.

The skin device measures 1 square centimeter. The system contains 100 small sensors that attempt to recreate things like texture (质地), temperature and even pain. The researchers call the device Asynchronous Coded Electronic Skin, or ACES, which can process information faster than humans' nervous system. Machine learning methods trained the device to recognize 20 to 30 different textures. It can even correctly read Braille letters most of the time, the researchers say.

The system does not require the users' movement to work. Humans need to slide to feel texture. But in this case the skin, with just a single touch, is able to detect textures of different roughness.

A demonstration showed that the device could identify the difference between a soft ball and a solid plastic one. "When you lose your sense of touch, you essentially become numb and prosthetic users face that problem, " said Benjamin Tee, leader of the research team. "So by recreating an artificial version of the skin, for their prosthetic devices, they can hold a hand and feel the warmth and feel that it is soft."

Tee said his idea for the device came from the movie Star Wars, when character Luke Skywalker loses his right hand and it is replaced with a robotic one. In the film, the new hand is able to experience touch sensations just like the real one.

The artificial skin technology is still going through experiments and development. But Tee said there had already been a lot of interest in the system, especially from the medical community. Tee said similar inventions that his team has developed include see-through skin that can repair itself when torn and a material for wearable electronic devices that gives off light.