新概念英语85年上外美音版第四册 第9课
时间：2018-12-24 作者：英语课 分类：新概念英语85年上外美音版
Lesson 9 Curiosities of Animal Life 动物生活趣闻
Not all sounds made by animals serve as language, and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly 1 utilitarian 2 role.
To get a full appreciation 3 of what this means we must turn first to some recent human inventions. Everyone knows that if he shouts in the vicinity of a wall or a mountainside, an echo will come back. The further off this solid obstruction 4 the longer time will elapse for the return of the echo. A sound made by tapping on the hull 5 of a ship will be reflected from the sea bottom, and by measuring the time interval 6 between the taps and the receipt of the echoes the depth of the sea at that point can be calculated. So was born the echo-sounding apparatus 7, now in general use in ships. Every solid object will reflect a sound, varying according to the size and nature of the object. A shoal of fish will do this. So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish. With experience, and with improved apparatus, it is now possible not only to locate a shoal but to tell if it is herring, cod 8, or other well-known fish, by the pattern of its echo.
A few years ago it was found that certain bats emit squeaks 9 and by receiving the echoes they could locate and steer 10 clear of obstacles--or locate flying insects on which they feed. This echo-location in bats is often compared with radar 11, the principle of which is similar.
- His doctor is dieting him strictly.他的医生严格规定他的饮食。
- The guests were seated strictly in order of precedence.客人严格按照地位高低就座。
- On the utilitarian side American education has outstridden the rest of the world.在实用方面美国教育已超越世界各国。
- A good cloth coat is more utilitarian than a fur one.一件优质的布外衣要比一件毛皮外衣更有用。
- I would like to express my appreciation and thanks to you all.我想对你们所有人表达我的感激和谢意。
- I'll be sending them a donation in appreciation of their help.我将送给他们一笔捐款以感谢他们的帮助。
- She was charged with obstruction of a police officer in the execution of his duty.她被指控妨碍警察执行任务。
- The road was cleared from obstruction.那条路已被清除了障碍。
- The outer surface of ship's hull is very hard.船体的外表面非常坚硬。
- The boat's hull has been staved in by the tremendous seas.小船壳让巨浪打穿了。
- The interval between the two trees measures 40 feet.这两棵树的间隔是40英尺。
- There was a long interval before he anwsered the telephone.隔了好久他才回了电话。
- The school's audio apparatus includes films and records.学校的视听设备包括放映机和录音机。
- They had a very refined apparatus.他们有一套非常精良的设备。
- They salt down cod for winter use.他们腌鳕鱼留着冬天吃。
- Cod are found in the North Atlantic and the North Sea.北大西洋和北海有鳕鱼。
- The upper-middle-classes communicate with each other in inaudible squeaks, like bats. 那些上中层社会的人交谈起来象是蚊子在哼哼，你根本听不见。 来自辞典例句
- She always squeaks out her ideas when she is excited. 她一激动总是尖声说出自己的想法。 来自互联网