Lesson 7 Bats-英语听力mp3下载无损flac下载
Lesson 7 Bats-英语听力在线试听免费歌词下载
[00:01.47]Lesson 7
第七节 [00:03.39]Bats
蝙蝠 [00:11.30]In what way does echo-location in bats play an utilitarian role?
蝙蝠的回声定位在哪些方面有重大实用价值? [00:19.78]Not all sounds made by animals serve as language
动物发出的声音不都是用作语言交际 [00:24.17]and we have only to turn to that extraordinary discovery of echo-location in bats
我们只要看一看蝙蝠回声定位这一极不寻常的发现 [00:30.34]to see a case in which the voice plays a strictly utilitarian role.
就可以探究一下声音在什么情况下有绝对的实用价值 [00:36.35]To get a full appreciation of what this means
要透彻理解这句话的意义 [00:39.73]we must turn first to some recent human inventions.
我们应先回顾一下人类最近的几项发明 [00:44.50]Everyone knows that if he shouts in the vicinity of a wall or a mountainside,
大家都知道，在墙壁或山腰附近发出的喊声 [00:49.97]an echo will come back.
就会听到回声 [00:52.57]The further off this solid obstruction,
固体障碍物越远 [00:55.01]the longer time will elapse for the return of the echo.
回声返回所用时间就越长 [00:59.16]A sound made by tapping on the hull of ship will be reflected from the sea bottom
敲打船体所发出的声音会从海底传回来 [01:05.35]and by measuring the time interval between the taps and the receipt of the echoes the depth of the sea at that point can be calculated.
测出回声间隔的时间，便可算出该处海洋的深度 [01:15.11]So was born the echo-sounding apparatus, now in general use in ships.
这样就产生了目前各种船舶上普遍应用的回声探测仪 [01:21.77]Every solid object will reflect a sound,
任何固体者反射声音 [01:25.65]varying according to the size and nature of the object.
反射的声音因物体的大小和性质的不同而不同 [01:30.09]A shoal of fish will do this.
鱼群也反射声音 [01:32.95]So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.
从测定海深到测定鱼群，这一进展比较容易 [01:40.85]With experience, and with improved apparatus,
根据经验和改进了的仪器 [01:44.48]it is now possible not only to locate a shoal but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.
不仅能够确定鱼群的位置，而且可以根据鱼群回声的特点分辨出是鲱鱼、鳕鱼，这是人们所熟悉的其他鱼 [01:56.28]It has been found that certain bats emit squeaks and by receiving the echoes,
人们发现，某些蝙蝠能发出尖叫声，并能通过回声 [02:02.42]they can locate and steer clear of obstacles -- or locate flying insects on which they feed.
来确定并躲开障碍物，或找到它们赖以为生的昆虫 [02:09.96]This echo-location in bats is often compared with radar,
蝙蝠这种回声定位常常可与雷达相比较 [02:14.16]the principle of which is similar.
其原理是相似的
第七节 [00:03.39]Bats
蝙蝠 [00:11.30]In what way does echo-location in bats play an utilitarian role?
蝙蝠的回声定位在哪些方面有重大实用价值? [00:19.78]Not all sounds made by animals serve as language
动物发出的声音不都是用作语言交际 [00:24.17]and we have only to turn to that extraordinary discovery of echo-location in bats
我们只要看一看蝙蝠回声定位这一极不寻常的发现 [00:30.34]to see a case in which the voice plays a strictly utilitarian role.
就可以探究一下声音在什么情况下有绝对的实用价值 [00:36.35]To get a full appreciation of what this means
要透彻理解这句话的意义 [00:39.73]we must turn first to some recent human inventions.
我们应先回顾一下人类最近的几项发明 [00:44.50]Everyone knows that if he shouts in the vicinity of a wall or a mountainside,
大家都知道，在墙壁或山腰附近发出的喊声 [00:49.97]an echo will come back.
就会听到回声 [00:52.57]The further off this solid obstruction,
固体障碍物越远 [00:55.01]the longer time will elapse for the return of the echo.
回声返回所用时间就越长 [00:59.16]A sound made by tapping on the hull of ship will be reflected from the sea bottom
敲打船体所发出的声音会从海底传回来 [01:05.35]and by measuring the time interval between the taps and the receipt of the echoes the depth of the sea at that point can be calculated.
测出回声间隔的时间，便可算出该处海洋的深度 [01:15.11]So was born the echo-sounding apparatus, now in general use in ships.
这样就产生了目前各种船舶上普遍应用的回声探测仪 [01:21.77]Every solid object will reflect a sound,
任何固体者反射声音 [01:25.65]varying according to the size and nature of the object.
反射的声音因物体的大小和性质的不同而不同 [01:30.09]A shoal of fish will do this.
鱼群也反射声音 [01:32.95]So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.
从测定海深到测定鱼群，这一进展比较容易 [01:40.85]With experience, and with improved apparatus,
根据经验和改进了的仪器 [01:44.48]it is now possible not only to locate a shoal but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.
不仅能够确定鱼群的位置，而且可以根据鱼群回声的特点分辨出是鲱鱼、鳕鱼，这是人们所熟悉的其他鱼 [01:56.28]It has been found that certain bats emit squeaks and by receiving the echoes,
人们发现，某些蝙蝠能发出尖叫声，并能通过回声 [02:02.42]they can locate and steer clear of obstacles -- or locate flying insects on which they feed.
来确定并躲开障碍物，或找到它们赖以为生的昆虫 [02:09.96]This echo-location in bats is often compared with radar,
蝙蝠这种回声定位常常可与雷达相比较 [02:14.16]the principle of which is similar.
其原理是相似的
Lesson 7 Bats-英语听力热门评论
comparatively,相当地。emit，发射。steer clear of,避开。in general use,普遍使用。serve as,充当。
utilitarian＝practical,实用的。vicinity,附近。elapse,消逝。tap on＝hit,敲击。apparatus,仪器。shoal＝a school of fish,鱼群。
众志成城、战胜Bats疫情。不出门不聚会，乖乖在家学英语。2/6/2020
嗯，，， 武汉加油！ （只有我一个人在2020年看到这篇文章吗？）
好像少了一句话——在the longer time will elapse for the return of the echo后面应该是A sound made by tapping on the hull of a ship will be reflected from the sea bottom, and by measuring.....后面就ok了
