The deadliest Ebola outbreak in history that has so far killed almost 1000 people in Guinea, Liberia, Sierra Leone and Nigeria in West Africa has caused fear around the world.

    The outbreak is unprecedented（空前的）both in infection numbers and in geographic scope. Officials from the World Health Organization (WHO) said earlier this month the outbreak “is moving faster than our efforts to control it”, reported CNN. So far, the battle against the virus doesn't appear to be slowing down.

    The Ebola virus is terrifying no matter where it strikes: It's a disease with no cure that causes headaches and fever, severe diarrhea(腹泻), vomiting and bleeding and has been known to kill up to 90 percent of its victims.

    It is understandable for people to be panicked, but those living outside Africa shouldn't be particularly concerned about contracting the virus, says a Washington Post article.

    This is because transmission of Ebola requires direct contact with an infected person's blood, vomit or other bodily fluids during the period that he or she is contagious(接触传染的). It is something that is extremely unlikely for anyone but healthcare workers. The virus is not spread by coughing or sneezing.

    Media outlets in the US and the UK are using terrifying headlines, wrongly claiming that people infected with the virus have traveled to their countries.

    James Ball at The Guardian says the Ebola outbreak in Africa is tragic, but it is important to keep a sense of proportion. Other infectious diseases, including common influenza, are far, far deadlier.

    Grown­ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins “Twinkle, twinkle, little star” or remember the story of Cinderella or Goldilocks and the Three Bears.

    One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, additional learning trials(尝试)increase the length of time we will remember it.

    In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as “Twinkle, twinkle, little star” and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

    The multiplication tables(乘法口诀表)are an exception to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.

    The law of overlearning explains why cramming(突击学习)for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.

    It was Saturday morning. I heard loud noises of moving furniture in the next room. I could almost feel the excitement of John who was soon going to get a room of his own. I remember my own feelings when I was 13. I knew how much he longed for his right to privacy (私人空间) when he was sharing a room with his younger brother, Robot. He said, “Mum, Can I please have a room of my own? I could use Jeff's. He won't mind.”

    It was true that Jeff had graduated from college and flown from the nest. But would he mind? The room was the place where I told him a thousand stories and we had a thousand talks. As close as we were, though, the time came when Jeff needed a door between us. His life was spreading into areas that had less to do with family. I no longer could-or should-know everything about him.

It turned out that getting Jeff's permission was easy. He said, “Of course, Mum, it would be selfish of me to hold on to it.” Then his voice softened, “Mum, I won't be living at home again—you know that.” Behind his glasses, his eyes were lit with all the love. There were no doors closed here—they had all opened up again.

    As John and I were cleaning the room, I fixed my eyes on Jeff's things around me and could almost touch the little boy who I knew was gone forever. I looked at the room and, in my heart, I let it go. To hold on would be, as Jeff said, selfish. Now it was time for John, shouldering through the door, his eyes bright with promise of independence, to disappear behind the door. It was time for letting go to happen again.

    The Marches were a happy family. Poverty, hard work, and even the fact that Father March was away with the Union armies could not down the spirits of Meg, Jo, Beth, Amy, and Marmee, as the March girls called their mother.

    The March sisters tried to be good but had their share of faults. Pretty Meg was often displeased with the schoolchildren she taught; boyish Jo was easy to become angry; golden-haired schoolgirl Amy liked to show up; but Beth, who kept the house, was loving and gentle always.

    The happy days passed and darkness came when a telegram arrived for Mrs. March. “Your husband is very ill,” it said, “come at once.” The girl tried to be brave when their mother left for the front. They waited and prayed. Little Beth got scarlet fever（猩红热）when she was taking care of the sick neighbor. She became very ill but began to recover by the time Marmee was back. When Father came home from the front and at that joyful Christmas dinner they were once more all together.

    Three years later the March girls had grown into young womanhood. Meg became Mrs. Brooke, and after a few family troubles got used to her new state happily. Jo had found pleasure in her literary efforts. Amy had grown into a young lady with a talent for design and an even greater one for society. But Beth had never fully regained her health, and her family watched her with love and anxiety.

    Amy was asked to go and stay in Europe with a relative of the Marches'. Jo went to New York and became successful in her writing and had the satisfaction of seeing her work published there. But at home the bitterest blow was yet to fall. Beth had known for some time that she couldn't live much longer to be with the family and in the spring time she died.

    News came from Europe that Amy and Laurie, the grandson of a wealthy neighbor, had planned to be married soon. Now Jo became ever more successful in her writing and got married to Professor Bhaer and soon afterwards founded a school for boys.

    And so the little women had grown up and lived happily with their children, enjoying the harvest of love and goodness that they had devoted all their lives to.

    In Alaska, the US, the grizzly bears are not alone because of Timothy Treadwell. Everyone knows that grizzly bears can be very dangerous to people. However, people can be perilous to grizzly bears, too, because their fur and food are beneficial for some people. In fact, half of the grizzly bears die before they are five years old, even though they can live for about 30 years.

    Grizzly bears hibernate every winter. They sleep for several months. During this period, they don't wake up or eat anything. When they wake up in the spring, the grizzlies are in danger. But Timothy can protect them. He sleeps in a tent near the bears and bathes in a river with them. People do not hurt the bears when Timothy is with them.

    Timothy went to Alaska for the first time about 17 years ago. He was attracted by the beauty of the land and the prettiness of the animals. When he learned that people kill many grizzly bears every year, Timothy determined to protect the grizzly bears and to keep the bears safe from danger, so he lives with the bears for four to five months every year. At the beginning, Timothy's parents didn't agree, but later, they firmly supported him to do so, because they also wanted to protect bears as him.

    Timothy has lived with the grizzlies every spring for about 17 years. Some bears are now his friends. He gave them names. His friend Booble sometimes gives him fish which he likes. His friend Lazy sleeps near his tent every night. Every winter, when the bears hibernate, Timothy returns to his home in California. Then he teaches children and adults about his friends in Alaska.

    You may think there are no differences between British and American people. After all, they speak the same language, don't they? If you ask a British or an American person, he will probably tell you that there are differences. And the differences are quite great.

    What do British people think American people are like? The British think American people are very strange. They make a lot of noise and they laugh too loudly. They are rich, and they only think about money. But the British do say that American people are kind, and friendly people. They're happy to help you if you are in trouble.

    What do Americans think of the British? Well, they think the British are cold and very unfriendly. They are not interested in success or in making lots of money. They think British is the best country in the world. They look down on other countries. But Americans say that the British are quite hard workers. They are brave and honest. And in time of trouble they face difficulties happily.

    You can see that these ideas can cause misunderstanding between the British and Americans. But when American and British people become friends, they usually find things are not as bad as they expected.