布什告别演说回顾过去展望未来 (1)

科学60秒:

2011 is the International Year of Chemistry. So scientists at the national meeting of the American Chemical Society in Anaheim ___1___. (Or a beaker.) And they celebrated as only chemists can—by...

科学60秒:热带雨林坍塌，爬行动物激增

The November 26th issue of the journal Science included a study showing that the extinction of the dinosaurs some 65 million years ago allowed ____1____ mammals to get really big. But well before

社会：美国失业率攀升至25年来最高峰

社会：美国失业率攀升至25年来最高峰The Labor Department is reporting the nation’s unemployment rate has now hit 8. 1%. That is the highest level we’ve seen in more than 25 years. The report stat...

经济：奥巴马致华尔街：别抵制金融改革

经济：奥巴马致华尔街：别抵制金融改革Aiming his appeal directly at the financial industry and skeptics within it, and at Republican critics in Congress, the president warned of the danger of a rep...