The Internet has opened up a whole new online world for us to meet, chat and go where we've never been before.

    But just as in face to face communication, there are some rules of behavior that should be followed when on line. {#blank#}1{#/blank#} Imagine how you'd feel if you were in the other person's shoes.

    For anything you're about to send: ask yourself, “Would I say this to the person's face? If the answer is no, rewrite and reread. {#blank#}2{#/blank#}

    If someone in the chat room is rude to you, your instinct (本能 ) is to fire back in the same manner. But try not to do so. {#blank#}3{#/blank#} If it was caused by a disagreement with another member, try to fix the situation by politely discussing it. Remember to respect opinions of others in the chat room.

    {#blank#}4{#/blank#} Offer advice when asked by newcomers, as they may not be sure what to do or how to communicate. When someone makes a mistake, whether it's a stupid question or an unnecessarily long answer, be kind about it. If it is a small mistake, you may not need to say anything. Having good manners yourself doesn't give you license to correct everyone else. {#blank#}5{#/blank#} At the same time, if you find you are wrong, be sure to correct yourself and apologize to those you have offended.

    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.

    On Monday, the Centers for Disease Control and Prevention predicted that 42% of Americans could be overweight by 2030. Our expanding waistlines lead to not only a medical problem, but according to a recent article In The New York Times, it could also endanger personal safety in some situations—in an airplane crash, for example.

    The New York Times' Christen Negroni reports that engineers and scientists are questioning whether airplane seats are adequately constructed to protect overweight travelers. Government standards for airplane seat strength（强度）— first set moe than 60 years ago — require that the seats be made for a passenger weighing 170 pounds (77kg). Today, the average American man weighs nearly 194 pounds (88kg) and the average woman 165 pounds (75kg). Negroni reports:

    “If a heavier person completely fills seat, the seat is not likely to behave as intended during a crash,” said Robert Salazar, the leading scientist at the Center for Applied Biomechanics at the University of Virginia. “The energy absorption that is built into the aircraft seat is likely to be overpowered and the passengers will not be protected properly.”

    “Nor would the injury be limited to that passenger only,” Dr. Salzar said. “If a seat or a seat belt fails,” he said, “those people who are seated nearby could be endangered from ‘the uncontrolled movements of the passenger'.”

    Most complaints about airplane seats focus on their lack of comfort and high ticket price, and whether overweight passengers should be made to buy two seats. But The New York Times' article brings up another reason to feel anxious about flying. Investigators of the issue got in touch with the airplane seat and seat belt makers, but they refused to comment on the problem. Experts agreed that crash testing should be done with overweight dummies （人体模型）. Both airplane seats and seat belts should be tested, they said.

    Fortunately, however, according to Nora Marshall, a senior adviser at the National Transportation Safety Board, the board's investigators have never seen an accident involving a commercial plane in which the weight of a passenger was a problem.

    Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.

    One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.

    Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.

    Homer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.

    Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.

    Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer's theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.

    According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.

    The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK's University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”

    As is often the case, however, there are others who find the theory less convincing. Cambridge University's paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It's only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.

    You can start horse-riding at any age. Choose private or group lessons any weekday between 9 am and 8:30 pm (3:30 pm on Saturdays). There are 10 kilometres of tracks and paths for leisurely rides across farmland and open country. You will need a riding hat.

    Opening Hours: Monday through Friday: 9:00 am一8:30 pm

    Phone: (412)396--6754 Fax: (412)396—6752

    Sailing Club:

    Our Young Sailor's Course leads to the Stage 1 Sailing qualification. You'11 learn how to sail safely and the course also covers sailing theory and first aid. Have fun with other course members afterwards in the clubroom. There are 10 weekly two—hour lessons (Tuesdays 6 pm～8 pm).

    Opening Hours: Tuesdays: 6:00 pm一8:00 pm

    Phone: (412)396—6644 Fax: (412)396—6644

    Diving Centre:

    Our experienced instructors offer one-month courses in deep-sea diving for beginners. There are two evening lessons a week, in which you learn to breathe underwater and use the equipment safely. You only need a swimming costume and towel. Reduced rates for couples.

    Opening Hours: Monday and Friday: 6:30pm—8:30pm

    Phone: (412)396—6312 Fax: (412)396—6706

    Medical Center:

    The staff of the Medical Center aim to provide convenient and comprehensive medical care to students and staff of the university. The center is well equipped and the staff here are trained to deal with a broad range of medical problems. Both female and male doctors as well as nursing staff are available for consultation. Also, all kinds of medicines are sold here and are cheaper for students than other drugstores.

    Opening Hours: 24 hour from Monday to Sunday

    Phone: (412)396—6649 Fax: (412)396—6648

    Watersports Club:

    We use a two-kilometre length of river for speedboat racing, and water-skiing. A beginners' course consists of ten 20-minute lessons. You will learn to handle boats safely and confidently, but must be able to swim. The club is in a convenient central position and is open daily from 9 a.m. to 4 p.m., with lessons all through the day.

Opening Hours: Monday through Friday: 9 am—4pm

Phone: (412)396--6899 Fax: (412)396—6890

    Four of the World's Best Futurists(未来学家)

    Kevin Kelly

    Kevin Kelly is an author. His 1994 publication, Out of Control, discusses a future where machines and systems are so complex as to be indistinguished(难区分的) from living things.

    His latest book What Technology Wants suggests that technology is not just a mixture of wires and metals but a living thing that has its own need. The book looks out through the eyes of this global technological system to discover what it wants.

    Dr Michio Kaku

    Dr Michio Kaku is a professor of theoretical physics at the City of New York and author of The Future of the Mind and Physics of the Future.

    In The Future of the Mind , he explores the frontier of neuroscience. He predicts that one day we will be able to upload the human brain into a computer. In Physics of the Future, he predicts that glasses and contact lenses will be connected to the Internet and cars will become driverless with the power of the GPS system.

    David Brin

    Science fiction author and scientist, David Brin has received awards. In 1998, he won the Freedom of Speech Award for The Transparence Society. The book concerns threats to personal affairs and openness in the information age. In a world where the police monitor public places 24 hours a day with cameras and some credit companies can sell people's financial details to anyone willing to pay, Brin warns that surveillance(监控) technology will be used by too few people in the future. He argues that the tables should be turned and the public should have access to information like who is buying financial details from credit companies.

    Dr Ray Kurzweil

    Dr Ray Kurzweil is the main inventor of the first print-to-speech reading machine for the blind. He is the director of artificial intelligence development at Google.

    Over the past 25 years, a number of his predictions have come true. In 1990, he predicted a computer would defeat a human at chess by 1998.He predicts that by the 2020s, most diseases will go away and self-driving cars begin to take over the roads.