Transportation is the movement or conveying of persons and goods from one loc

游客2023-12-22  24

问题    Transportation is the movement or conveying of persons and goods from one location to another. As human beings, from ancient times to the 21st century, sought to make their transport facilities more efficient, they have always endeavored to move people and property with the least expenditure of time, effort and cost. Primitive human beings supplemented their own carrying of goods and possessions by starting to domesticate animals—training them to bear small loads and pull crude sleds. The invention of the wheel, probably in western Asia, was a great step forward in transport. As the wheel was perfected, crude carts and wagons began to appear in the Tigris-Euphrates valley about 3,500 B. C. , and later in Crete, Egypt, and China. Wheeled vehicles could not use the narrow paths and trails used by pack animals, and early roads were soon being built by the Assyrians and the Persians. The greatest improvements in transportation have appeared in the last two centuries, a period during which the Industrial Revolution has vastly changed the economic life of the entire world. Crude railways—horse-drawn wagons with wooden wheels and rails—had been used in English and European mines during the 17 th century. Although it first appeared in England, the railroad had its most dramatic growth in the; United States. By 1840 more than 4,800 km of railroad were already operating in the eastern states, a figure 40 percent greater than the total railroad mileage of Europe. Since World War I, however, the U. S. railroads have been in a decline, due partly to the rapid development of private automobiles, trucks, buses, pipelines, and airlines. The first new mode of transportation to challenge the railroad was the motor vehicle, which was made possible by the invention, in the 1860s and ’70s, of the internal combustion engine. The automobile found its greatest popularity in the United States, where the first "horseless carriages" appeared in the 1890s. Two hundred million motor vehicles had been produced in the nation within 70 years of their first appearance. The automobile thus became in many ways as important to the 20th century as the railroads had been to the 19th. During the same period intercity buses took over a large portion of commercial passenger travel, and trucks began carrying a great deal of the nation’s freight. Although the emphasis on fuel conservation waned in the 1980s, few doubt that the issue will emerge again when oil scarcities loom, as they did in the 1970s. Future possibilities include automobiles with far greater fuel efficiency and improved mass-transit systems. Both will occur not only in response to oil-supply disruption, but also as an answer to increasing demands for cleaner air. Improvements in mass transit offer the most promise for the future. Amtrak’s 1993 introduction of the Swedish high-speed "tilting train" should cut travel time between some East Coast cities by almost half, once tracks are entirely electrified. [br] The phrase "tilting train" (para. 6) suggests that______.

选项 A、It carries more freight than other vehicles
B、It requires its tracks to be electrical
C、Its speed demands cleaner air
D、Its cost is very low

答案 B                                               

解析
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