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Why Study Mathematics 　　There’s something else you shouldn’t forget. There are lots of times when more math would help you in your everyday affairs. 　　No long ago a man in Milwaukee was arrested for speeding. The policeman, who had been stationing at a street comer, didn’t check the speed on the man’s motorcycle, but just guessed at it. (46). 　　The man said that he had stopped his car at the traffic light on the corner where the policeman was stationed. (47). 　　The driver then proved mathematically that no car could have picked up speed fast enough to be exceeding the limit at the spot where he was arrested. The judge let him off. (48). You may be the kind of person who needs to know something about advanced math to get the most out of life. Some people go on from day to day, having a good time and not caring much about anything else. (49). 　　They are interested in life and other people, and what makes things happen the way they do. __ (50). 　　If you are that kind of person, you almost have to learn something about the more advanced branch of math. There will be no other way to understand the things you become curious about.

A. The policeman admitted this.　　
B. But many people are not content to live that way.　　
C. They are curious about things.　　
D. But there is one more reason why you should study math now.　　
E. The man admitted this.　　
F. The man and the policeman went before a judge in the police court.

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Endangered SpeciesEndangered species are plants and animals that are in immediate danger of extinction. Extinction is actually a normal process in the course of evolution. Since the formation of the earth, many more species have become extinct than those exist today. These species slowly disappeared because of change of climate and their failure to adapt to such conditions as competition and predation. Since the 1600s, however, the process of extinction has greatly accelerated as a result of both human population growth and technological encroachment on natural ecology systems. Today the majority of the world’s environments are changing faster than the ability of most species to adapt to such changes through natural selection.Species become extinct or endangered for number of reasons, but the primary cause is the destruction of natural habitats. Drainage of wetlands, cutting and clearing of forests, growth of cities, and highway and dam construction have seriously reduced available natural habitats. As the various surroundings become fragments, the remaining animal population crowd into smaller areas, causing further destruction of natural surroundings. Species in these small “islands” lose contact with other populations of their extinction.Some private and government efforts have been organized to save declining species. Laws were made in some countries in the early 1900s to protect wild animals from commercial trade and killing. International endeavors are shown in the convention on International Trade in Endangered Species, approved by 51 nations. Its purpose is to restrict exploitation of wild animals and plants by regulating and restricting trade in certain species. How effective such laws will be in various countries, however, depends on enforcement and support by the people and the courts. Because of lack of law enforcement, the willingness of some segments of society to trade in endangered species, the activities of people who catch and kill animals illegally and dealers who supply the trade, the future of many species is in doubt in spite of legal protection.

A．Human beings are not aware of the importance of preserving endangered species.
B．Some endangered species have already reached the end of their life span in evolution.
C．The development of human society has greatly affected natural ecology systems.
D．The world’s climate has changed greatly that most species cannot survive.