练习材料：
Lesson 29-1 The hovercraft
Many strange new means of transport have been developed in our century, the strangest of them being perhaps the hovercraft. In 1953, a former electronics engineer in his fifties, Christopher Cockerell, who had turned to boat-building on the Norfolk Broads, suggested an idea on which he had been working for many years to the British Government and industrial circles. 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. Ever since, people have had difficulty in deciding whether the craft should be ranged among ships, planes, or land vehicles -- for it is something in between a boat and an aircraft. 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. His answer was to lift the vessel out of the water by a great number of ring-shaped air jets on the bottom of the craft.
本世纪已研制出许多新奇的交通工具，其中最新奇的要数气垫船了。1953年，有一位50多岁名叫克里斯托弗.科克雷的原电子工程师，改行在诺福克郡的湖泊地区从事造船业，他向英国政府和工业界提出了他研究多年的一项计划。他的设想是：用一个低压空气或软垫来支撑船体，软垫周围用高压空气环绕。自那以后，人们很难决定是否应该将这种运载工具列为轮船、飞机，或是陆上交通工具，因为它是介于船和飞机之间。作为一个船舶技师，科克雷尔在寻找解决波浪阻力的方法，因为波浪阻力浪费掉了船在水面行驶的大量动力，从而限制了船的速度。他的解决办法是把船体提离水面，让船在一个气垫上行驶，气垫只有一两英尺厚。船底装上大量环状喷气嘴以实现这一目的。
任务配置：L0、L3、L4
知识笔记：
单词与短语
练习感悟：坚持 ，完成。
网友评论