Earlier this month, two rock climbers achieved what many thought impossible: They climbed up the 3,000-foot-high Dawn Wall in Yosemite NationalPark without specialized equipment. Climbing without this equipment iscalled“free-climbing.”Until now, no one had free-climbed to the top of the rockface, which is a part of the mountain EI Capitan.

    El Capitan, which means“the captain”or“the chief”in Spanish, has always presented a challenge to climbers. But the Dawn Wall, on the mountain's southeast face, is a particularly difficult route to the summit (顶峰). It is a rock formation that is both steep and relatively smooth. This makes free-climbing the rock face seem almost impossible.

    About seven years ago, professional climber Tommy Caldwell spotted a possible route up the wall. It took years of planning and preparation, but this month, Caldwell, 36, and his friend Kevin Jorgeson, 30, finally make the climb.

    Free climbers do use ropes and other basic safety equipment to catch them if they fall — and Caldwell and Jorgeson fell often. Before starting their climb, they broke down their route into 32 sections. Each section was based on a rope length called a“pitch.”The rope was secured into the rock faceto catch the climbers if they fell.

    Caldwell and Jorgeson's goal was to climb the DawnWall without returning to the ground. If they fell, they had to start that pitch all over again. The two men started climbing on December 27. They slept in hanging tents, and a team of friends brought them food each day.

    The men had spent years rehearsing (排练) them ovements it would take to get through each pitch. They made it through the fist half of the climb relatively easily. But halfway up, Jorgeson ran into trouble. In one difficult spot, he fell each time he attempted to climb. After10 days of trying, Jorgeson finally made it to the next pitch.

    Getting through that troublesome pitch gave both climbers renewed energy. They finished the rest of the climb five days later, on January 14.

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components,” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing the components together. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, and then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Teachers in some secondary schools in Britain are worried that their job may become impossible shortly unless something can be done to restore discipline in the classrooms. In the problem schools, mostly in large cities, a small minority of teenage pupils disturb lesson to such an extent that the teacher can no longer teach their classes effectively.

    Some people consider that the permissive (随意) nature of modern society is responsible for such kind of behavior. Small children who are continuously encouraged to express themselves without reservation are naturally unwilling to accept school discipline when they grow older. Furthermore, modern teaching techniques) which appear to stress personal enjoyment at the expense of serious study work, might be teaching the child to put his own interests before his duties to the community in which he lives.

    Perhaps the problem can be solved by improving facilities for the moral guidance of these difficult children or by better cooperation between the schools and the parents—for the parents may be mainly responsible for the bad behavior of their youngsters. Violence at home, violence and crime on TV make some children turn violence themselves.

    But some of the teachers believe that there ought to be a return to more “old fashioned” methods. At present, in some school teachers are even not allowed to punish a child who does something bad and wrong. Physical punishment is not permitted now. People are too soft on children these days. It seems that children can do whatever they like at school while the teachers can't do anything to punish them. I don't know why the schools authority abandoned some of the effective punishments that worked well. Things like that didn't happen when we were at school because the teachers kept those problem students under control by using a stick.

    Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experience? Strangely enough, the answer to these questions is yes. To some degree our intelligence is given to us at birth, and no amount of education can make a genius out of a child born with low intelligence. On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings. Thus the limits of person's intelligence are fixed at birth, whether or not he reaches those limits will depend on his environment. This view, now held by most experts, can be supported in a number of ways.

    It is easy to show that intelligence is to some degree something we are born with. The closer the blood relationship between two people, the closer they are likely to be intelligent. Thus if we take two unrelated people at random from population, it is likely that their degree of intelligence will be completely different. If, on the other hand, we take two identical twins, they will very likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth. Imagine now that we take two identical twins and put them in different environments. We might send one, for example, to a university and the other to a factory where the work is boring. We would soon find differences in intelligence developing, and this indicates that environment as well as birth plays a part. This conclusion is also suggested by the fact that people who live in close contact with each other, but who are not related at all are likely to have similar degree of intelligence.

    In China, there are more and more people leaving the countryside to hunt for jobs in the cities, because the countryside is much poorer than the city, and often there isn't much work there. Services such as hospital and transport are usually much better in the city than in the countryside. They hope that their lives will improve when they move to the city.

    But in the big cities of Europe like London or Paris, people are moving out of the city. These rich families want to live a quieter life. They are tired of the noise and the dirt of the city, and they are tired of the crowded streets, crowded trains and buses. They don't want to live in the cities any more. They want a house with a garden in the countryside, and breathe the fresh air there. So they move out of the cities. Some don't go very far, just a little way out of the city, to the towns near the cities. Other people move to the real countryside with sheep, cows and green fields. There they start new lives and try to make new friends.

    Not all those who move from the city to the countryside are happy. After two or three years, many people who have done this feel that it is a big mistake. They don't make so much money and there isn't much work to do. People in the countryside are different and aren't always very friendly. As a result, quite a lot of people who have moved to the countryside move back to the city. “It's wonderful to see crowds in the streets and cinema lights.” they say.

    If there is one person who has left a deep impression on me, it's my teacher Mrs. Pathak who was my class teacher for three years. In my childhood, how I wished I had a mother or a sister like her. One moment she could be tough (严厉的) and strict, another moment caring and compassionate (富有同情心的).

    She always encouraged us to tell the truth. For instance, if one had not done the homework, he need not lie. She allowed us to make mistakes, saying we couldn't be perfect all the time, but we should try.

    Another thing she taught me early on was punctuality. She set a good example with her own behaviour. She was always on time, so we students tried our best to be on time.

    She surprised us with her sense of humour. Her classroom teaching was always humorous. After class, she talked to us and told us jokes.

    We really felt free to ask questions and Mrs. Pathak would give the answers. If she did not know — there had been some occasions (场合) — she would say so. We all then tried to find out the answers. Whoever came up with the answer was appreciated and given the due credit (应有的称赞). Now I sometimes wonder whether Mrs. Pathak was pretending just to encourage us to explore and find answers by ourselves.