【1】A safari park is a park in which wild animals are kept. They are mainly located in east or central Africa. They often occupy a very wild area, with mountains and rivers. To visit the park and look at the animals, people have to drive around in a car for a few of hours because the park is huge.

【2】In south Africa there is a safari park, which contains all sorts of wild animals like lions, elephants, rhinoceroses(犀牛), zebras, wild pigs, deer and giraffes.

【3】There is a wild road leading through the park, but nobody is permitted to walk on the road. Anyone traveling in the park has to go in a car because wild animals may fiercely attack people. From the car he may see almost every types of African wildlife. Some of these are getting scarce (稀有的) because people kill them for various reasons. For example, rhinoceroses are killed for their horns (角), which are used in traditional Chinese medicines for colds and headaches. Perhaps they will be seen only in museums and books one day.

【4】Travels may buy food for the animals. They can feed them when they tour the park. Of course, they should not feed them in a close distance because the wild animals may attack people. In addition, they should only give proper food to the animals.

【5】A traveler may carry a gun with him in his journey. The gun is given to him by the government. However, it is not used for hunting. In fact, a seal(封条) is fixed to it. The traveler may fire at a wild beast to defend himself in case he is attacked. However, he has to prove to the government that he has been attacked and that he has not fired at a harmless animal.

    From self-driving cars to carebots for elderly people, rapid development in technology has long represented a possible threat to many jobs normally performed by people. But experts now believe that almost 50 percent of occupations existing today will be completely unnecessary by 2025 as artificial intelligence continues to change businesses.

    "The next fifteen years will see a revolution in how we work, and a revolution will necessarily take place in how we plan and think about workplaces," said Peter Andrew, Director of Workplace Strategy for CBRE Asia Pacific.

    A growing number of jobs in the future will require creative intelligence, social skills and the ability to use artificial intelligence.

    The report is based on interviews with 200 experts, business leaders and young people from Asia Pacific, Europe and North America. It shows that in the US technology already destroys more jobs than it creates.

    But the report states: "Losing occupations does not necessarily mean losing jobs — just changing what people do." Growth in new jobs could occur as much, according to the research.

    "The growth of 20 to 40 person companies that have the speed and technological know-how will directly challenge big companies," it states.

    A 2014 report by Pew Research found 52 percent of experts in artificial intelligence and robotics were optimistic about the future and believed there would still be enough jobs in the next few years. The optimists pictured "a future in which robots do not take the place of more jobs than they create," according to Aaron Smith, the report's co-author.

    "Technology will continue to affect jobs, but more jobs seem likely to be created. Although there have always been unemployed people, when we reached a few billion people there were billions of jobs. There is no shortage of things that need to be done and that will not change," Microsoft's Jonathan Grudin told researchers.

Life in the Clear

Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet—as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, "These animals live through their life alone. They never touch anything unless they're eating it, or unless something is eating them."

And they are as clear as glass. How does an animal become see-through? It's trickier than you might think.

    The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter (散射) light, bouncing it away from its original path. Others absorb light, stopping it dead in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily.

    But a transparent object doesn't absorb or scatter light, at least not very much. Light can pass through it without bending or stopping. That means a transparent object doesn't look very different from the surrounding air or water. You don't see it you see the things behind it.

    To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments (色素) that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.

Animals are built of many different materials—skin, fat, and more—and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see-through. Others build a large, clear mass of non-living jelly-like (果冻状的) material and spread themselves over it.

    Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear: for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.

    Making friends is a skill like many other skills. It improves with practice. If you want to meet people and make friends，you must be willing to take some actions. You must first go where there are people. You won't make friends staying home alone. Join a club or a group. Talking with those who like the same things as you do is much easier. Or join someone in some activities. Many people are nervous when talking to new people. After all meeting strangers means facing the unknown. And it's human nature to feel a bit uncomfortable about the unknown. Most of our fears about dealing with new people come from doubts about ourselves. We imagine other people are judging us or finding us too tall or too short，too this or too that. But don't forget that they must be feeling the same way. Try to accept yourself as you are and try to put the other person at ease. You'll both feel more comfortable.

    Try to act self­confidently even if you don't feel that way. When you enter a room full of strangers，such as a new classroom，walk tall and straight，look directly at other people and smile.

    If you see someone you'd like to speak to，say something. Don't wait for the other person to start a conversation.

    Just meeting someone new does not mean that you will make friends with that  person—friendship is based on mutual liking and“give and take”. It takes time and effort to develop.

    Some inventions are so useful, but seem so simple, that we wonder why no one thought of them long ago. Post-it Notes, the pieces of paper that you can stick almost anywhere and then remove without leaving any sign that they are there, are an example of such an invention.

    Post-it Notes were invented about twenty years ago by Art Fry, a scientist at 3M Corporation. The idea for the product came from an upsetting experience he often had while singing in his church choir. Fry used pieces of paper as bookmarks to mark the places in his book of songs, but these bookmarks were always falling out. He knew he needed a bookmark that would stay where he put it, but that he could remove without damaging the pages.

    Around that time, Fry heard about a new adhesive(粘合剂) that a colleague, Dr. Spence Silver had created. This adhesive was special because it was sticky, but not too sticky. It was strong enough to hold papers together, but weak enough not to tear the paper when it was removed. Fry saw that the new adhesive could help solve his bookmark problem. One morning, Fry put some of the adhesive on the edge of a piece of paper. Just as he hoped, it made a perfect bookmark.

    A short time later, Fry realized that his new invention had even more uses than being a great bookmark. He came to this realization when he wrote a note on one of his new “bookmarks” and attached it to a report he was going to give to a colleague. Soon, co-workers were asking Fry for more sample of his invention so that they could use the new type of notes themselves.

    Fry and some other people at 3M believed so much in the new product that they persuaded the company to give away thousands of the sticky pieces of paper for trial use. When some salespeople at 3M went to offices and showed workers just how helpful the new type of notes could be, they immediately received many orders. As more and more people discovered how useful Post-it Notes could be, the product took off.

    The plan: turn Mars into a blue world with streams and green fields, and then fill it with creatures (生物) from the earth. This idea may sound like something from a science fiction (科幻小说), but it is actually being taken seriously by many researchers.

    This suggested future for the "red planet" will be the main topic for discussion at an international conference hosted by NASA (美国宇航局) this week. Leading researchers as well as science fiction writers will attend the event. It comes as NASA is preparing a multi billion dollar Mars research programme. "Turning Mars into a little earth has long been a topic in science fiction," said Dr Michael Meyer, NASA's senior scientist for astrobiology (太空生物学). "Now, with scientists exploring the reality, we can ask what are the real possibilities of changing Mars."

    Most scientists agree that Mars could be turned into a little earth, although much time and money would be needed to achieve this goal.

    But many experts are shocked by the idea. "We are destroying our own world at an unbelievable speed and now we are talking about ruining another planet," said Paul Murdin, of the Institute of Astronomy, Cambridge, UK. Over the past months, scientists have become increasingly confident they will find Martian life forms. Europe and America's robot explorers have found proof that water, mixed with soil, exists in large amounts on the planet.

    In addition, two different groups of scientists announced on March 28 that they had found signs of methane (甲烷) in the Martian atmosphere (大气). The gas is a waste product of living creatures and could be produced by microbes (微生物) living in the red planet's soil.

    But scientists such as Dr Lisa Pratt, a biologist at Indiana University, say that these microbes will be put in danger by the little earth project. "Before we have even discovered if there is life on Mars, we are talking about carrying out projects that would destroy all these native life forms, all the strange microbes that we hope to find buried in the soil," said Dr Pratt. This view is shared by Monica Grady, a planetary scientist at the Natural History Museum, London. "We cannot risk starting a global experiment that would wipe out the precious information we are looking for." she said, "This is just wrong."