Question: Old people are easy to feel lonely because their children are busy with their work and have little time to spend with them.Most of them have to be companied by pet dogs.However,it is sometimes impossible for some old people to keep pet dogs because they are too old or ill to take care of pet dogs. Experts are studying the influence of robotic dogs on old people's depression ,physical activity,and life satisfaction.Researchers are placing robotic dogs in the homes of lonely old people to see whether they can improve the quality of life for old people.Alan Beck,an expert in human-animal relationship,said,"Old people should be more active,challenged,excited.The problem is how we promote that,especially for those without friends or help.A robotic dog could be a solution." In the study,the robot,called AIBO,is placed for six weeks in the houses of some old people who live alone.These old people will keep a diary to note their feelings and activities before and after AIBO.Researchers will collect basic data for six weeks.Then,the researchers will review the data to decide if there are any changes in the life of its owner. "I talk to him all the time,and he responds to my voice,"says a 70-year-old lady."When I'm watching TV,he'll stay in my arms until he wants down.He has a mind of his own." The AIBOs respond to certain orders.The researchers say they have some advantages over real dogs,especially for old people.Often the elderly are disabled and cannot care for an animal by walking it or playing with it.A robotic dog needn't any exercise and feeding concerns. "At the beginning,it was believed that no one would prefer the robotic dog because it was metal and not furry  ,"Beck says."But it's amazing how quickly we have given up that belief." Hopefully,these robotic pets could become a more valuable health helper.They will record their masters'blood pressure,oxygen levels,or heart rhythms.AIBOs may even one day have games that can help exciting older people's minds. The author may believe that the future robotic dogs can  . A) help excit old people's minds B) take the place of real dogs C) cure a lot of serious diseases D) change people's beliefs
Answer: B

Question: When different species of birds flock   together, their flight formations are determined by social dynamics both between and within species. New research from the Universities of Cambridge and Exeter reveals for the first time that, contrary to current models used to explain the movement of flocks, the differences between bird species and social relationships between individuals play a critical role in determining the dynamics of mixed-species flocks. The unified  behaviour of bird flocks has puzzled scientists for hundreds of years. One naturalist from the turn of the century even suggested telepathy may be involved. There have since been more logical explanations, including mathematical models that show that repeated interactions among individuals following simple rules can _ coordinated  group movements. However, these models usually rely on the assumption that individuals within groups are identical and interact independently, which may not reflect reality. Jolle Jolles, a PhD student at the University of Cambridge's Department of Zoology and author of the paper, said:"Spectacular collective behaviour can be found in a large range of animal species, and we now know that often these complex coordinated group movements may be the result of individuals following simple rules. However, rarely are the individual characteristics and social relationships within them taken into account. Our research highlights that these striking displays of group behaviour are much more complex." By analysing high-resolution photographs of mixed flocks of rooks and jackdaws (both from the corvid family), the researchers found that rather than individuals interacting in a consistent fashion throughout the flock, interactions depended on social dynamics between the different species as well as relationships within a species. The researchers discovered that birds prefer to fly close to members of their own species, and that the larger and more dominant rooks take the lead by flying near the front of flocks. Additionally, the... What is the main idea of the passage? A) How birds interact in simple rules. B) How birds of different feathers flock together. C) Why birds show preference to flocking. D) Why birds display the characteristics.
Answer: B

Question: One day, a train was approaching the small town of Cheekyville. On the train was a young man with a big suitcase. He was called William Warbler, and he looked very common indeed. What made him most unusual, though, was the fact that whenever he needed to communicate he did it by singing opera  . It didn't matter to William whether it was simply a matter of answering a brief greeting, like "good day". He would clear his voice and respond, "Gooood dayyy to youuuuuuuu... toooooo!" No one could get a normal spoken word out of him and no one knew how he made his living. As he lived quite simply, always wearing his same old second-hand suit, people often looked down on him. William had been in Cheekyville for some years, when, one day, word spread round town like wildfire: William had played a role in a very important opera in the nation's capital. Everyone in the capital went to see it, and it was a great success. Everyone in Cheekyville felt it was a surprise. But something more surprising was, when William was being interviewed by reporters, he answered their questions by speaking rather than singing. And he did it with great manners, and with a clear and pleasant voice. From that day, William gave up singing at all hours. Now he did it only during his stage appearances and world tours. Some people suspected why he had changed, but others continued believing him to be somewhat mad. They wouldn't have thought so if they had seen what William kept in his big suitcase. It was a large stone, with a hand-carved   message on it. The message said: "Practice, my boy. Practice every second, for you never know when your chance will come." Little did people realize that he only got the role in the opera because the director had heard William singing while out buying a newspaper. According to the text, William   _  . A) had no idea whether he should continue doing something mad B) was nervous and didn't know how to sing when he was interviewed C) was selling newspapers when the opera director heard him singing D) practiced singing whenever possible before he became famous
Answer:
D