[al:新概念英语（四）] [ar:MP3 同步字幕版（美音）] [ti:The Hovercraft] [by:更多学习内容，请到yingyu.chazidian.com搜索“新概念”] [00:01.06]Lesson 29 [00:02.96]The hovercraft [00:10.31]What is a hovercraft riding on when it is in motion? [00:16.55]Many strange new means of transport have been developed in our century, [00:22.29]the strangest of them being perhaps the hovercraft. [00:27.29]In 1953, a former electronics engineer in his fifties, Christopher Cockerell, [00:35.44]who had turned to boat-building on the Norfolk Broads, [00:39.52]suggested an idea on which he had been working for many years to the British Government and industrial circles. [00:48.13]It was the idea of supporting a craft on a 'pad', or cushion, of low-pressure air, ringed with a curtain of higher pressure air. [01:00.20]Ever since, people have had difficulty in deciding whether the craft should be ranged among ships, planes, [01:09.38]or land vehicles--for it is something in between a boat and an aircraft. [01:17.57]As a shipbuilder, Cockerell was trying to find a solution to the problem of the wave resistance which wastes a good deal of a surface ship's power and limits its speed. [01:31.54]His answer was to lift the vessel out of the water by making it ride on a cushion of air, no more than one or two feet thick. [01:42.60]This is done by a great number of ring-shaped air jets on the bottom of the craft. [01:49.60]It 'flies', therefore, but it cannot fly higher--its action depends on the surface, water or ground, over which it rides. [02:02.29]The first tests on the Solent in 1959 caused a sensation. [02:08.57]The hovercraft travelled first over the water, then mounted the beach, climbed up the dunes, and sat down on a road. [02:19.57]Later it crossed the Channel, riding smoothly over the waves, which presented no problem. [02:28.89]Since that time, various types of hovercraft have appeared and taken up regular service. [02:36.31]The hovercraft is particularly useful in large areas with poor communications such as Africa or Australia; [02:44.82]it can become a 'flying fruit-bowl', carrying bananas from the plantations to the ports; [02:51.89]giant hovercraft liners could span the Atlantic; [02:55.67]and the railway of the future may well be the 'hovertrain', [02:59.99]riding on its air cushion over a single rail, which it never touches, at speeds, up to 300 m.p.h.--the possibilities appear unlimited.