[新概念英语2短文]大学新概念英语精美短文（十）

【#新概念英语# 导语】新概念英语之所以经久不衰是因为以其全新的教学理念，有趣的课文内容和全面的技能训练，为英语学习者排忧解难，深受广大英语学习者的欢迎和喜爱。想要学好英语的你，怎能错过？快来加入学习吧！©文档大全网为您提供，希望以下内容能够为大家的新概念英语学习提供帮助!

【篇一】Statistics

There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping orderly records of governmental units (states and statistics come from the same Latin root status) and a gentlemanly gambling father who relied on mathematics to increase his skill at playing the odds in games of chance. The influence of the mother on the offspring, statistics, is represented by counting, measuring, describing, tabulating, ordering, and the taking of censuses-all of which led to modern descriptive statistics. From the influence of the father came modern inferential statistics, which is based squarely on theories of probability.

Descriptive statistics involves tabulating, depicting and describing collections of data. These data may be quantitative such as measures of height, intelligence or grade level -- variables that are characterized by an underlying continuum -- or the data may represent qualitative variables, such as sex, college major or personality type. Large masses of data must generally undergo a process of summarization or reduction before they are comprehensible. Descriptive statistics is a tool for describing or summarizing or reducing to comprehensible form the properties of an otherwise unwieldy mass of data.

Inferential statistics is a formalized body of methods for solving another class of problems that present great difficulties for the unaided human mind. This general class of problems characteristically involve attempts to make predictions using a sample of observations. For example, a school superintendent wishes to determine the proportion of children in a large school system who come to school without breakfast, have been vaccinated for flu, or whatever. Having a little knowledge of statistics, the superintendent would know that it is unnecessary and inefficient to question each child: the proportion for the entire district could be estimated fairly accurately from a sample of as few as 100 children. Thus, the purpose of inferential statistics is to predict or estimate characteristics of a population from a knowledge of the characteristics of only a sample of the population.

【篇二】译文

统计学

统计方法的早期发展受到两种截然不同的影响。统计学有一个“母亲”，她致力于井井有条地记录政府机构的文件（国家和统计学这两个词源于同一个拉丁语词根，status），还有一个有绅士般的赌博“父亲”，他依靠数学来提高赌技，以便在几率的游戏中取胜。“母亲”对其子女统计学的影响表现在计数、测量、描述、制表、归类和人口普查。所有这些导致了现代描述统计学的诞生。由于“父亲”的影响则产生了完全基于概率论原理的现代推理统计学。

描述统计学涉及对所收集数据的制表、制图和描述。这些数据可以是数量性的数据，如高度、智商、或者是层级性的数据——具有连续性的变量——或数据也可以代表性质变量，如性别、大学专业或性格类型等等。数量庞大的数据通常必须经过概括或删减的程序才能为人所理解。描述统计学就是这样一个工具，它对极其庞杂的数据进行描述、概括或删减，使其变成能为人理解的东西。

推理统计学是一套已定形了的方法体系，它解决的是光凭人脑极难解决的另一类问题。这类问题的显著特点是试图通过取样调查来作出预测。例如，有一位教育督察想知道在一个庞大的学校系统中，不吃早饭就上学的学生、已经做过防感冒免疫的学生，或其它任何类型的学生占多大比例。若具备一些统计学的知识，这位督察应明白，询问每个孩子是没有必要而且没有效率的，只要用100个孩子为样本，他就可以相当精确地得出这些孩子占整个学区的比例了。因此，推理统计学的目的就是通过了解一个群体中一些样本的特性，从而对整个群体的特性进行推测和估算。

【篇三】Coal-fired power plants

The invention of the incandescent light bulb by Thomas A. Edison in 1879 created a demand for a cheap, readily available fuel with which to generate large amounts of electric power. Coal seemed to fit the bill, and it fueled the earliest power stations (which were set up at the end of the nineteenth century by Edison himself). As more power plants were constructed throughout the country, the reliance on coal increased. Since the First World War, coal-fired power plants have accounted for about half of the electricity produced in the United States each year.

In 1986 such plants had a combined generating capacity of 289, 000 megawatts and consumed 83 percent of the nearly 900 million tons of coal mined in the country that year. Given the uncertainty in the future growth of nuclear power and in the supply of oil and natural gas, coal-fired power plants could well provide up to 70 percent of the electric power in the United States by the end of the century.

Yet, in spite of the fact that coal has long been a source of electricity and may remain one for many years (coal represents about 80 percent of United States fossil-fuel reserves), it has actually never been the most desirable fossil fuel for power plants. Coal contains less energy per unit of weight than natural gas or oil; it is difficult to transport, and it is associated with a host of environmental issues, among them acid rain. Since the late 1960's problems of emission control and waste disposal have sharply reduced the appeal of coal-fired power plants. The cost of ameliorating these environmental problems along with the rising cost of building a facility as large and complex as a coal-fired power plant, have also made such plants less attractive from a purely economic perspective.

Changes in the technological base of coal-fired power plants could restore their attractiveness, however. Whereas some of these changes are evolutionary and are intended mainly to increase the productivity of existing plants, completely new technologies for burning coal cleanly are also being developed.

【篇四】译文

火力发电厂

托马斯·爱迪生1879年发明的白炽灯导致对便宜、易得、可生产大量电能的燃料的需求。煤似乎符合这个要求，并成为第一批电厂的燃料（正是爱迪生本人在19世纪末建造了第一批电厂）。 全国到处兴建电厂时，对煤的依赖加深了。自第一次世界大战以来，美国每年约有一半的电力是以煤为燃料的电厂提供的。

1986年这些电厂的总发电能力达到28,900千瓦并且消耗了当年全国开采的九亿吨煤的83%。 考虑到核能发展以及石油、天然气供应中的不确定因素，到本世纪末，火力发电厂仍可能为美国提供多达70%的电力。

然而，尽管煤长期以来一直是电力的原料之一并且可能会继续如此（煤占美国化石燃料储量的80%），它却不是电厂的理想燃料。 煤的单位能量含量低于石油和天然气，而且会导致包括酸雨在内的一系列环境问题。 从1960年以来，排放控制和垃圾处理的问题极大地削弱了燃煤电厂的魅力。 由于减轻这些环境问题需要大量资金，而且建造庞大复杂的燃煤电厂的费用不断上涨，也使得这些电厂从经济角度上不具备吸引力。

改变火力发电厂的基础技术却可能恢复它们的吸引力。 虽然某些技术改进是渐进的，其目的只是提高现有电厂的生产率，但人们正在开发全新的清洁燃煤的技术。

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