北師大版高中英語模塊7--Unit 20 lessons3-2

[00:01.51]Einstein had already become world- famous [00:04.21]when a young ex-lawyer, [00:06.06]returning from the First World War, [00:08.04]started work at the Mount Wilson Observatory [00:10.39]in California.Using the most high-powered [00:13.50]telescope of the time,he began the long slow [00:16.57]process of exploring our galaxy. [00:19.48]Edwin Huble was about to make astronomy's [00:22.03]greatest breakthrough of the century. [00:24.43]He discovered nebulae [00:26.67]which were in fact galaxies like our won, [00:29.28]millions of light years away from us, [00:31.96]which proved that the universe was vastly [00:34.16]larger than had previously been thought. [00:36.91]Then,Hubble proved that the universe [00:39.05]is actually expanding, [00:40.95]and that the futher away galaxies are, [00:42.93]the faster they move. [00:45.50]In 1929,another far-reaching finding [00:48.43]was made by the son of a Scottish shepherd. [00:51.18]Before he went on holiday, [00:52.98]Alexander Fleming left a dish [00:54.77]with bacteria in it near the window [00:56.93]of his laboratory.When he came back, [00:59.14]he was just about to throw the dish away [01:01.41]when he noticed something our of the ordinary. [01:04.28]He double-checked and saw a blue mould [01:06.52]in the dish around [01:07.78]which the bacteria had been destroyed. [01:10.76]This blue moud was in fact the natural [01:13.41]form of pencicillin which Fleming realized [01:15.85]was an effective way of killing bacteria. [01:17.72]

00:00

00:00

MP3下載 文本下載