It's what led patriots to choose republic over tyranny, pioneers to trek west, slaves to brave that makeshift railroad to freedom. 正是这一召唤引领着爱国者推翻暴政、选择共和，引领着西进运动，引领着勇敢的奴隶们建造通向自由的地下铁路。 It's what pulled

Another aha! moment came from a 2010 Wayne State University research project that looked into pre-1950s baseball cards of Major League players. 另一项令人顿悟的研究是由2010年韦恩州立大学进行的，这个项目研究了二十世纪五十年代前美国职业棒球联盟球员卡。

REMARKS BY THE PRESIDENT AND BEN BERNANKE AT THE NOMINATION OF BEN BERNANKE FOR CHAIRMAN OF THE FEDERAL RESERVEOak Bluffs School Filing CenterOak Bluffs, Massachusetts 8:55 A.M. EDT THE PRESIDENT: Goo

Fifteen years ago, a September day that began like any other became one of the darkest in our nation's history. 十五年前九月的一天，如同平常的日子却成为我们国家历史上最黑暗的一天。 The Twin Towers were reduced to rubble. 双子塔变成了瓦砾堆

Now, we're headed towards a world where robots are everywhere. 我们正迈入一个机器人无处不在的社会。 Robotic technology is moving out from behind factory walls. 机器人科技正在走出工厂的围墙。 It's entering workplaces, households. 它们正在