[al:新概念英语（四）] [ar:MP3 同步字幕版（英音）] [ti:The Hovercraft] [by:更多学习内容，请到chazidian.com搜索“新概念”] [00:01.55]Lesson 29 [00:03.46]The hovercraft [00:11.25]What is a hovercraft riding on when it is in motion? [00:17.57]Many strange new means of transport have been developed in our century, [00:22.14]the strangest of them being perhaps the hovercraft. [00:26.77]In 1953, a former electronics engineer in his fifties, Christopher Cockerell, [00:34.08]who had turned to boat-building on the Norfolk Broads, [00:37.87]suggested an idea on which he had been working for many years [00:42.15]to the British Government and industrial circles. [00:45.90]It was the idea of supporting a craft on a 'pad', or cushion, of low-pressure air, [00:53.92]ringed with a curtain of higher pressure air. [00:57.78]Ever since, people have had difficulty in deciding [01:01.28]whether the craft should be ranged among ships, planes, or land vehicles -- [01:07.60]for it is something in between a boat and an aircraft. [01:12.26]As a shipbuilder, [01:13.66]Cockerell was trying to find a solution to the problem of the wave resistance [01:18.68]which wastes a good deal of a surface ship's power and limits its speed. [01:24.61]His answer was to lift the vessel out of the water [01:28.09]by making it ride on a cushion of air, no more than one or two feet thick. [01:34.95]This is done by a great number of ringshaped air jets on the bottom of the craft. [01:41.73]It 'flies', therefore, but it cannot fly higher--its action depends on the surface, water or ground, over which it rides. [01:53.81]The first tests on the Solent in 1959 caused a sensation. [01:59.78]The hovercraft travelled first over the water, then mounted the beach, [02:04.58]climbed up the dunes, and sat down on a road. [02:08.98]Later it crossed the Channel, riding smoothly over the waves, [02:13.43]which presented no problem. [02:16.47]Since that time, [02:17.95]various types of hovercraft have appeared and taken up regular service. [02:23.27]The hovercraft is particularly useful in large areas with poor communications [02:29.10]such as Africa or Australia; [02:32.28]it can become a 'flying fruit-bowl', [02:35.28]carrying bananas from the plantations to the ports; [02:38.98]giant hovercraft liners could span the Atlantic; [02:43.10]and the railway of the future may well be the 'hovertrain', [02:48.02]riding on its air cushion over a single rail, which it never touches, [02:53.47]at speeds, up to 300 m.p.h.--the possibilities appear unlimited.