1803 年 4 月,美国特使门罗与法国签订《路易斯安那购买条约》: 以1500万美元(约合今日 3.4 亿美元 )购得从密西西比河到落基山脉的 82.8 万平方公里 土地。 一夜之间,美国的领土几乎翻倍,从“东部小国”变成横跨大陆的“潜在强国”。
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NASA’s $20 Million Mission to the “God of Chaos” Asteroid Set to Launch After Major ...
NASA’s ambitious OSIRIS-APEX mission to study the asteroid Apophis has been spared from cancellation, but its future is far ...
According to a study conducted by University of Tokyo researchers, Ryugu maintained a "pristine record" of late water activity. By examining the lutetium and hafnium isotopes in their rock samples, ...
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