I grew up poor. We had little money, butplenty of love and attention. I understood that no matter how poor a person was, they could still afford a dream. My dream was athletics.

    By the time I was sixteen, I was good at baseball and football. My high-school coach was Ollie Jarvis. He not only believed in me, but taught me the difference between having a dream and showing conviction（信念）.

    One summer a friend recommended me for asummer job. This meant a chance for money in my pocket — cash for dates withgirls, certainly, money for a new bike and new clothes, and the start of savings for a house for my mother.

Then I realized I would have to give up summer baseball to handle the work schedule, and that meant I would have to tell Coach Jarvis I wouldn't be playing. I was dreading（害怕）this, but my mother said: "If you make your bed, you have to lie in it."

When I told Coach Jarvis, he was as madas I expected him to be. "Your playing days are limited. You can't afford to waste them," he said.

   I stood before him with my head hanging, trying to think of the words that would explain to him why my dream of buying my mom a house.

"How much are you going to make at this job, son?" he demanded.

"Three twenty-five an hour," I replied.

"Well," he asked, "is $3.25 an hour the price of a dream?"

    That question laidbare for me the difference between wanting something right now and having agoal. I devoted myself to sports that summer, and within the year I was drafted by the Pittsburgh Pirates to play rookie-league ball, and offered a $20,000 contract. I signed with the Denver Broncos in 1984 for $1.7 million, and boughtmy mother the house of my dream.

A few years ago, I read about an eight-year-old girl who studied elephant poaching in school and made a poster for her local grocery store. The slogan read, "Save the elephants. Don't buy Ivory Soap, or they will die out." What the girl had done taught me a lesson. Since then, I have looked at eight-year-olds in a different way. As an environmental educator, I used to teach eight-year-olds about the harm of elephant poaching, rainforest destruction, and global warming. I had a degree in natural science—but not in child development. What did I think I was accomplishing by putting my environmental concerns on the shoulders of kids who still believe in fairy tales?

Kids develop the fear of nature when their primary contact with the natural world is hearing bad news about the environment. If I wanted to inspire conservation action, I needed to change my ways, but now? I came across a research by psychologist Louise Chawla. She wanted to know what had gone on in the childhoods of adults who are good environmental citizens. She found two things most common. They had free time to explore the rivers or woods down the street, and they had an adult in their lives who was enthusiastic about the natural world. I understand now that what turned me into a good person today was a childhood spent playing in the field and having a dad who knew that finding a lobster under a rock was better than finding treasure.

    So that's what I was doing when I was eight years old—looking under rocks, climbing trees, and picking wild .flowers. I didn't know a thing about the Clean Air Act that was being debated in congress at that time. I didn't hear a lot of environmental problems. But I built a relationship with nature and I grew up to care. Now I treat my own kids like the child I was. My kids turn off the water when they brush their teeth and turn off the lights when they leave a room.

    Riding School:

    You can start horse—riding at any age. Choose private or group lessons any weekday between 9:00 a.m. and 8:30 p.m.(3:30 p.m. on Saturdays). There are 10 kilometers 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 a.m.—8:30 p.m.

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

    Sailing Club:

    Our Young Sailor's Course leads to the Stage 1 Sailing qualification. You'll learn how to sail safely and the course also covers sailing theory and first aid. Have fun with other course member, afterwards in the clubroom. There are 10 weekly two-hour lessons(Tuesdays 6:00 p.m.—8:00 p.m.).

    Opening Hours: Tuesdays: 6:00 p. m.—8:00 p.m.

    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 swimming suits and a towel. Reduced rates for couples.

    Opening Hours: Monday and Friday: 6:30 p.m.—8:30 p m.

Hollywood's theory that machines with evil(邪恶) minds will drive armies of killer robots is just silly. The real problem relates to the possibility that artificial intelligence(AI) may become extremely good at achieving something other than what we really want. In 1960 a well-known mathematician Norbert Wiener, who founded the field of cybernetics（控制论）, put it this way: “If we use, to achieve our purposes, a mechanical agency with whose operation we cannot effectively interfere(干预), we had better be quite sure that the purpose put into the machine is the purpose which we really desire.”

A machine with a specific purpose has another quality, one that we usually associate with living things: a wish to preserve its own existence. For the machine, this quality is not in-born, nor is it something introduced by humans; it is a logical consequence of the simple fact that the machine cannot achieve its original purpose if it is dead. So if we send out a robot with the single instruction of fetching coffee, it will have a strong desire to secure success by disabling its own off switch or even killing anyone who might interfere with its task. If we are not careful, then, we could face a kind of global chess match against very determined, super intelligent machines whose objectives conflict with our own, with the real world as the chessboard.

The possibility of entering into and losing such a match should concentrate the minds of computer scientists. Some researchers argue that we can seal the machines inside a kind of firewall, using them to answer difficult questions but never allowing them to affect the real world. Unfortunately, that plan seems unlikely to work: we have yet to invent a firewall that is secure against ordinary humans, let alone super intelligent machines.

Solving the safety problem well enough to move forward in AI seems to be possible but not easy. There are probably decades in which to plan for the arrival of super intelligent machines. But the problem should not be dismissed out of hand, as it has been by some AI researchers. Some argue that humans and machines can coexist as long as they work in teams—yet that is not possible unless machines share the goals of humans. Others say we can just “switch them off” as if super intelligent machines are too stupid to think of that possibility. Still others think that super intelligent AI will never happen. On September 11, 1933, famous physicist Ernest Rutherford stated, with confidence, “Anyone who expects a source of power in the transformation of these atoms is talking moonshine.” However, on September 12, 1933, physicist Leo Szilard invented the neutron-induced(中子诱导) nuclear chain reaction.

    After retirement, Michael Kennedy could have chosen to take walks around his seaside home. Instead, the former mechanical engineer engaged himself in the toughest task of his life - keeping the thundering waves of the Norfolk coast.

    The 73-year-old has spent the past 14 years building his own sea wall at Hunstanton, piling up rocks picked from the sandy beach to slow the erosion （侵蚀）of the soft limestone （石灰岩）and chalk cliffs. It's estimated that Michael has shifted 200 tons of stone in the last 14 years.

    “It's a real labour of love because I come down here whatever the weather, in spring, summer, autumn and winter,” said the divorced father of two. “It keeps me fit and I love it.”

    Mr Kennedy moved to the area after retiring from the London Underground. Nicknamed Fred Flintstone by locals, he tries to move at least 40 pounds of rocks in two-hour sessions which he finishes by 2 pm.

    Everything he collects is placed into piles at the foot of the cliffs. Larger rocks go at the bottom to provide the main line of defence and smaller ones are placed at the top. He also picks up rubbish and prides himself on having created a spotless, stone-free sandy beach for holidaymakers to enjoy.

    The work goes on six days a week. Saturdays are his day off so that the Chelsea “fanatic” can watch football and other sports. However, there are signs that he is becoming a victim of his own success, as the number of stones has dwindled significantly in recent months.

    “It's confusing, Mr Kennedy said. “Usually every year the stones just come in with the sea but this year we haven't had any.” He added, “I hope to still be doing it when I'm 100 but perhaps just four days a week instead of six.”

    Town mayor Peter Mallam said Mr Kennedy had become “quite a local legend”. “It's fascinating. Everyone knows of the old guy who collects the stones. He's done a sterling effort.”

A 293-million-mile journey of the NASA Perseverance rover (探测器) to Mars: ended successfully on February 18, 2021, with a picture-perfect landing inside the Jezero Crater. The car-sized, six-wheeled rover, nicknamed Percy is the US space agency's biggest and most advanced explorer to date. Its primary mission is to search for signs of ancient microbial (微生物的) life on Mars.

Landing on Mars is extremely tricky. The Red Planet's gravitational pull causes approaching spacecraft to go faster to high speeds, while its thin atmosphere-just 1 percent that of Earth's-does little to help slow it down as it approaches the surface.

The scientists had to reduce Percy's 12,000 mph speed to a safe landing speed of less than five mph-in just six and a half minutes. The target entry angle also had to be a precise 12 degrees-any steeper, and the spacecraft would burn up; any flatter, and it would get lost in space. It is no wonder that the final approach is often referred to as the "seven minutes of terror. "

Upon attaining a manageable speed, Percy briefly flew over the Martian surface to seek out the perfect landing spot. Its complex map-reading system rapidly scanned the area and matched it with maps in its database to find the best location.

The NASA scientists will spend the next two months testing Percy's scientific instruments. Once ready, the rover will begin to carry out its mission.

"Perseverance is the smartest robot ever made, but confirming that microbial life once existed carries an unusually large burden of proof," said Lori Glaze, director of NASA's Planetary Science Division. "While we'll learn a lot with the great instruments we have aboard the rover, it may very well require the far more well-equipped laboratories and delicate instruments back here on Earth to tell us whether our samples (样本) carry evidence that Mars once harbored life. "