One day，Mr.Arnold was teaching a lesson，and things were going as normally as ever.He was explaining the story of mankind to his pupils.He told them that，in the beginning，men were nomads(游牧人)；they never stayed in the same place for very long.Instead，they would travel about，here and there，in search of food，wherever it was to be found. And when the food ran out，they would move off somewhere else.

He taught them about the invention of farming and keeping animals.This was an important discovery，because by learning to cultivate(耕作)the land，and care for animals，mankind would always have food steadily available.It also meant that people could remain living in one place，and this made it easier to set about tasks that would take a long while to complete，like building towns，cities，and all that were in them.All the children listening were attracted by this story，until Lucy jumped up：

    “And if that was so important and improved everything so much，why are we nomads all over again，Mr.Arnold？”

    Mr.Arnold didnt know what to say. Lucy was a very intelligent girl.He knew that she lived with her parents in a house，so she must know that her family were not nomads；so what did she mean?

“We have all become nomads again，” continued Lucy.“The other day，outside the city，they were cutting the forest down. A while ago a fisherman told me how they fish.Its the same with everyone：when theres no more forest left, the foresters go elsewhere，and when the fish run out, the fishermen move on.Thats what the nomads did，isnt it？”

The teacher nodded,thoughtfully. Really,Lucy was right. Mankind had turned into nomads. Instead of looking after the land in a way that we could be sure it would keep supplying our needs，we kept developing it until the land was bare.And then off we would go to the next place！The class spent the rest of the afternoon talking about what they could do to show how to be more civilized.

    The next day everyone attended class wearing a green T-­shirt，with a message that said，“I am not a nomad！”

    And，from then on，they set about showing that indeed they were not.Every time they knew they needed something，they made sure that they would get it using care and control.If they needed wood or paper，they would make sure that they got the recycled kind.They ordered their fish from fish farms，making sure that the fish they received were not too young and too small.They only used animals that were well cared for，and brought up on farms.

    And so，from their little town，those children managed to give up being nomads again，just as prehistoric men had done so many thousands of years ago.

    When I left my bag on a train, I lost my most precious possession, a small framed photograph of my great grandparents, Emily and Gordon Baker. The frame was made of silver, with an elegant flower design in one corner. The photograph was taken in March 1939 0n their wedding day. Emily looked very happy, and Gordon looked rather a larmed.  A few months later, he was killed in action in North Africa. I received the photograph when my aunt Mabel died.

    I'm a student at Edinburgh University and I live in an old Edwardian house.  At the end of last term, I packed a large bag and a small bag and set off for London, where I was planning to catch the Eurostar train to Paris. Minutes after getting off the train at Kings Cross Station, I realized that I'd left the small bag in the overhead luggage rack. I ran back to the train, but it had already left the platform. www..com

    This all happened several months ago, and I had become resigned to the loss of my most precious possession. then last week, something extraordinary happened. I logged onto the site ~ eBay and looked for a silver photo frame and I found it ! The photo of my great grandparents was on eBay !

    I called the person who was advertising it.   He was a little suspicious(怀疑 )  at first, and told me that he had bought it from a stall at an antique market. After we talked for a while, he asked if there was any way I could prove it was mine. All I could think of was that the photo was taken in March 1939. He opened the frame and made sure that this date was written by hand on the back of the photograph.

    “It's definitely yours. " he said.  "Come and get it ! "

    Louis Pasteur was born in Dole, France on December 27, 1822. His family was poor, and during his early education Pasteur was an ordinary student who enjoyed art and singing. However, when Pasteur was exposed to science as a teenager, he knew he had found his career.

    In 1838, Pasteur went to college to become a science teacher. He then became a chemistry professor at the University of Strasbourg. He got married in 1849 and had five children. However, three died young from typhoid fever (伤寒症). It was the deaths of his children that drove Pasteur to investigate the infectious disease in order to find a cure.

    During Pasteur's time, people believed that bacteria (细菌) appeared due to “spontaneous generation (自然发生)”. They thought that the bacteria just appeared out of nowhere. Pasteur earned out experiments to see if this was true. Through his experiments he proved that germs (细菌) were living things that came from other living things. They didn't just spontaneously appear. This was a major discovery in the study of biology and earned Pasteur the title of Father of Germ Theory.

    As Pasteur learned more about bacteria, he began to think they may be the cause of diseases in humans. When the French silk market was threatened by a disease to silkworms (蚕), Pasteur decided to investigate. He discovered that this disease was caused by germs. By killing them from the silkworm farms, he was able to cease the disease and save the French silk business.

    Today Louis Pasteur is known as one of the most important scientists in history. His discoveries led to an understanding of bacteria and diseases that has helped save millions of lives.

    One night about nine o'clock, Dr. Eyck, a surgeon, had a phone call from Dr. Haydon at the hospital in Clens Falls. The surgeon was asked to go there at once to operate on a very sick boy who shot himself while playing with a gun.

    The doctor was soon on his way to Clens Falls. It was 60 miles away. And it was snowing heavily in the city. The surgeon thought he could get there before 12 o'clock.

    A few minutes later, the doctor was stopped by a man in an old black coat. Gun in hand, the man ordered the doctor to get out. Then the man drove the car down the road, leaving the doctor in the falling snow.

    It was after 2 o'clock in the morning when the doctor arrived at the hospital in Clens Falls. Dr. Haydon told him that the boy had died an hour before.

    The two doctors walked by the door of the hospital waiting room. There sat the man in the old black coat with his head in his hands.

    "Mr. Cuninghan," said Dr. Haydon to the man, "This is Dr. Eyck. He is the surgeon who walked all the way from Albany to save your boy."

    The days of the hunter are almost over in India. This is partly because there is practically nothing left to kill, and partly because some steps have been taken, mainly by banning tiger-shooting, to protect those animals which still survive.

    Some people say that Man is naturally a hunter. I disagree with this view. Surely our earliest forefathers, who at first possessed no weapons, spent their time digging for roots, and were no doubt themselves often hunted by meat-eating animals.

    I believe the main reason why the modern hunter kills is that he thinks people will admire his courage in overpowering dangerous animals. Of course, there are some who truly believe that the killing is not really the important thing, and that the chief pleasure lies in the joy of the hunt and the beauties of the wild countryside. There are also those for whom hunting in fact offers a chance to prove themselves and risk death by design; these men go out after dangerous animals like tigers, even if they say they only do it to rid the countryside of a threat. I can respect reasons like these, but they are clearly different from the need to strengthen your high opinion of yourself.

    The greatest big-game hunters expressed in their writings something of these finer motives. One of them wrote.

    "You must properly respect what you are after and shoot it cleanly and on the animal's own territory(领地)。You must fix forever in your mind all the wonders of that particular day. This is better than letting him grow a few years older to be attacked and wounded by his own son and eventually eaten, half alive, by other animals, Hunting is not a cruel and senseless killing - not if you respect the thing you kill, not if you kill to enrich your memories, not if you kill to feed your people."

    I can understand such beliefs, and can compare these hunters with those who hunted lions with spears(矛) and bravely caught them by the tail. But this is very different from many tiger-shoots I have seen, in which modern weapons were used. The so-called hunters fired from tall trees or from the backs of trained elephants. Such methods made tigers seem no more dangerous than rabbits.

    Eye Health Care

    Daily

    Healthy habits mean healthy eyes. Here are some daily tips for eye health.

    P Clean your eyes with pure cold water regularly. This is one of the best ways to keep eyes healthy and disease free.

    Avoid looking directly at the sun

    Roll your eyes up and down, then side to side. Then move your eyes in a circular motion（圆周运动） Exercise5tol0 times a day to relax your eyes

    Keep a good distance from the computer screen-sit about 22-28 inches away from it.

    Visit your eye doctor on a regular basis

    There are also some tips for healthy contact lens（隐形眼镜）wear and care to help prevent eye infections (感染). Please visit CDCS healthy contact lenses website and you can also follow them on social media(www.cdc.goy/contactlenses).