单词：improved main rotor blades
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[00:07.58]Igor Sikorsky was born in the city of Kiev, Russia; on May 25, 1889. [00:16.12]His mother was a doctor. [00:15.12]His father was a professor of psychology. [00:18.59]Igor became interested in science when he was very young. [00:23.82]He was
美国英语听力80篇
By Jim Fry Washington 03 May 2007 Marine Osprey The U.S. Marines are preparing to send a new tilt rotor aircraft into combat for the first time. And the American manufacturer predicts a civilian version may soon appear over many of the world's citie
2007年VOA标准英语（五月）
This is Scientific American's 60-Second Science, I'm Cynthia Graber. This will just take a minute. It sounds like the title to a Rudyard Kipling tale: how the turtle got its shell. But its actually a question that has puzzled scientists. After all, n
Scientific American(七)月
1. The man accused of kidnapping two young boys has pleaded not guilty in one of the cases. Michael Devlin went before a judge this morning in the case of Ben Ownby. Meantime, the parents of Shawn Hornbeck, the other teen he's accused of kidnapping,
美联社新闻一分钟2007