题目

（2016甘肃省兰州市）如图，A，B两点在反比例函数的图象上，C、D两点在反比例函数的图象上，AC⊥x轴于点E，BD⊥x轴于点F，AC=2，BD=3，EF=，则=（ ）A. 4 B. C. D. 6 答案：【答案】A【解析】设A（m，），B（n，），则C（m，），D（n，），由题意：，解得=4．故选A．The similarities between elephant and human behavior has been a curiosity to scientists worldwide. These huge beasts are not so different from us. Their devotion to their family is just as powerful as the friendships between humans. In order to prevent future elephant attacks, people must first understand the similarities between elephants and themselves.Because deaths are felt so deeply in elephants, memories of people harming or killing other members are not forgotten. Due to the Uganda-Tanzania War in Africa, poaching (偷猎) elephant increased during the 1970’s and continued, despite government restrictions. However, ecologists like Eve Abe did not see this as simple poaching; they saw it as a “mass destruction. “Elephants that have witnessed the murder of a matriarch, are more likely to become violent and attack humans. Many aggressive elephants do not act without reason; they are suffering from Post Traumatic Stress Disorder (PTSD). At a young age, humans invade their life, kill their parents, and ultimately destroy their peaceful environment. More and more calves live neglected lives without a mother figure, and have to become a parent early for survival. Humans that had a difficult childhood or early family life also suffer from aggression and pain. Young elephants have been known to have “nightmares,” waking up suddenly and screaming. These are clearly signs of stress, as males grow up to be increasingly hostile (敌对的) humans and target certain villages where painful experiences had occurred.Although many see elephants as massive, violent, and simple-minded animals, their social structure is not unlike many human societies. Humans and elephants have been on parallel paths. However, if people continue practicing ignorance over the cruel treatment of these creatures, then collision will become inevitable. Cruel treatment of elephants still goes on, but by understanding the similarities between us, it can be stopped.【1】In order to stop the hostile behavior of elephants, people should lay emphasis on ________.A. stopping harming or killing the group members of elephantsB. understand the similarities between elephants and humansC. taking good care of the young elephantsD. carrying out the government restrictions【2】What does the underlined word “matriarch” mean?A. young elephant.B. male elephant.C. strong elephant.D. mother elephant.【3】What can we infer from the passage?A. Young elephants will grow up to be violent easily.B. Humans and elephants have the same social structure.C. Sometimes young elephants are forced to grow up.D. Elephants attack villages when painful experiences occur.【4】Why should we take good care of the young kids?A. Because early family life counts.B. Because they will be aggressive when grown up.C. Because humans and elephants are on parallel paths.D. Because signs of stress have to be stopped.