新概念英语85年上外美音版第四册 第9课

　　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 strictly¹ utilitarian² role.
To get a full appreciation³ 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 obstruction⁴ the longer time will elapse for the return of the echo. A sound made by tapping on the hull⁵ of a ship will be reflected from the sea bottom, and by measuring the time interval⁶ 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 apparatus⁷, 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, cod⁸, or other well-known fish, by the pattern of its echo.
A few years ago it was found that certain bats emit squeaks⁹ and by receiving the echoes they could locate and steer¹⁰ clear of obstacles--or locate flying insects on which they feed. This echo-location in bats is often compared with radar¹¹, the principle of which is similar.
 

1 strictly   

adv.严厉地，严格地；严密地

参考例句：

• 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。

2 utilitarian   

adj.实用的，功利的

参考例句：

• 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。

3 appreciation   

n.评价；欣赏；感谢；领会，理解；价格上涨

参考例句：

• 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。

4 obstruction   

n.阻塞，堵塞；障碍物

参考例句：

• 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。

5 hull   

n.船身；(果、实等的)外壳；vt.去(谷物等)壳

参考例句：

• 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。

6 interval   

n.间隔，间距；幕间休息，中场休息

参考例句：

• 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。

7 apparatus   

n.装置，器械；器具，设备

参考例句：

• 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。

8 cod   

n.鳕鱼；v.愚弄；哄骗

参考例句：

• 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。

9 squeaks   

n.短促的尖叫声，吱吱声( squeak的名词复数 )v.短促地尖叫( squeak的第三人称单数 )；吱吱叫；告密；充当告密者

参考例句：

• 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

10 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

11 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。