[by:英语听力网|http://yingyu.chazidian.com||查字典英语网] [00:00.00]喜欢chazidian.com，就把chazidian.com复制到QQ个人资料中！Lesson 17 [00:01.70]第17课 [00:03.40]Television Day:Computers [00:05.56]电视日:计算机 [00:07.73]"...the astronauts are returning to earth at exactly 5.24." [00:10.50]...宇航员将于5:24整回到地球, [00:13.27]Splash-down will be in the Pacific,427 miles west of Hawaii. [00:16.60]"并将在位于夏威夷西部427英里的太平洋海面上溅落." [00:19.93]You have often heard announcements like this on television. [00:22.36]你常会从电视听到上述的预告. [00:24.79]Scientists can tell us exactly [00:26.81]举例说,科学家能准确地告诉我们 [00:28.84]when a space-capsule will arrive on the moon for instance, [00:31.32]宇宙密封小舱何时抵达月球 [00:33.80]and exactly when it will return. [00:35.83]和何时返回. [00:37.85]They can calculate things like this to the nearest second. [00:40.42]对这类事情,他们的计算可精确至秒. [00:43.00]How do they do it? [00:44.38]他们是如何做的呢? [00:45.77]Well,of course,they use mathematics. [00:47.99]当然他们运用了数学. [00:50.21]We can all do simple sums on paper, [00:52.39]我们都能在纸上做简单的算术题, [00:54.57]but we must use computers for extremely difficult calculations. [00:57.55]但必须用计算机进行复杂的运算. [01:00.53]Perhaps you have seen mechanical calculating-machines in banks and offices. [01:03.61]你也许在银行和办公室见过机械计算机. [01:06.69]They can work very quickly,but nothing like computers. [01:09.37]尽管它们运算迅速,但与电子计算机截然不同. [01:12.05]Computers aren't mechanical. [01:13.91]电子计算机不是机械的. [01:15.78]They don't have wheels and gears in them. [01:17.96]它们没有转轮和齿轮. [01:20.14]Instead,they work on electrical circuits [01:22.57]而是通过电路工作的, [01:25.00]and can do difficult calculations at tremendous speed. [01:27.63]可以迅速进行复杂的运算 [01:30.25]They can work 100 million times faster than the human mind! [01:33.73]它们运算速度要比人脑快上一亿倍.