双语有声阅读：电子交通

Telecommuting Telecommuting -- substituting the computer for the trip to the job--has been hailed as a solution to all kinds of problems related to office work. For workers it promises freedom from the office, less time wasted in traffic, and help wi

双语有声阅读：化学的历史

The History of Chemistry Chemistry did not emerge as a science until after the scientific revolution in the seventeenth century and then only rather slowly and laboriously. But chemical knowdedge is as old as history, being almost entirely concerned

双语有声阅读：陶器

Pottery Ancient people made clay pottery because they needed it for their survival. They used the pots they made for cooking, storing food, and carrying things from place to place. Pottery was so important to early cultures that scientists now study

双语有声阅读：郊区的发展

Suburbanization If by suburb is meant an urban margin that grows more rapidly than its already developed interior, the process of suburbanization began during the emergence of the industrial city in the second quarter of the nineteenth century. Befor

双语有声阅读：统计学

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 (state and statistics come from the same Latin root stat

双语有声阅读：睡眠

Sleep Sleep is part of a person's daily activity cycle. There are several different stages of sleep, and they too occur in cycles. If you are an average sleeper, your sleep cycle is as follows. When you first drift off into slumber, your eyes will ro

双语有声阅读：摩天大楼与环境

Skyscrapers and Environment In the late 1960's,many people in North America turned their attention to environmental problems,and new steel-and-glass skyscrapers were widely criticized.Ecologists pointed out that a cluster of tall buildings in a city

双语有声阅读：科学理论

Scientific Theories In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is

双语有声阅读：学校与教育

Schooling and Education It is commonly believed in the United States that school is where people go to get an education.Nevertheless, it has been said that today children interrupt their education to go to school. The distinction between schooling an

双语有声阅读：饲养牡蛎

Raising Oysters In the past oysters were raised in much the same way as dirt farmers raised tomatoes - by transplanting them. First, farmers selected the oyster bed, cleared the bottom of old shells and other debris, then scattered clean shells about

双语有声阅读：人口增长

Population Growth The growth of population during the past few centuries is no proof that population will continue to grow straight upward toward infinity and doom. On the contrary, demographic history offers evidence that population growth has not b

双语有声阅读：警察与社区

Police and Communities Few institutions are more important to an urban community than its police, yet there are few subjects historians know so little about. Most of the early academic interests developed among political scientists and sociologists,

双语有声阅读：沙漠中的植物

Plants in the Deserts Some cacti, like the saguaro, grow to tree size, but true trees need more moisture than most desert environments can supply, so they are scarce on deserts. Close to streambeds, cottonwoods can sometimes be found. Though these st

双语有声阅读：浮游生物

Plankton Scattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They drift about lazily with the currents, providing a basic f

双语有声阅读：钢琴

Piano The ancestry of the piano can be traced to the early keyboard instruments of the fifteenth and sixteenth centuries -- the spinet, the dulcimer, and the virginal. In the seventeenth century the organ, the clavichord, and the harpsichord became t

双语有声阅读：炼油

Oil Refining An important new industry, oil refining, grew after the Civil War. Crude oil, or petroleum -- a dark, thick ooze from the earth -- had been known for hundreds of years, but little use had ever been made of it. In the 1850's Samuel M. Kie

双语有声阅读：板块结构与海床扩展

Plate Tectonics and Sea-floor Spreading The theory of plate tectonics describes the motions of the lithosphere, the comparatively rigid outer layer of the Earth that includes all the crust and part of the underlying mantle.The lithosphere is divided

双语有声阅读：生命的美好

The Goodness of Life Though there is much to be concerned about, there is far, far more for which to be thankful. Though lifes goodness can at times be overshadowed, it is never outweighed. For every single act that is senselessly destructive, there

双语有声阅读：面前的美好

丈夫平静地说：我什么也没写，我觉得像你这样就很完美了，我不想让你为我改变什么。你很可爱迷人，我不想让你改变。 A man and his girlfriend were married. It was a large celebration. All of their friends

双语有声阅读：想想美好的东西

Try to remember the good things When times become difficult (and you know they sometimes will), remember a moment in your life that was filled with joy and happiness. Remember how it made you feel, and you will have the strength you need to get throu