So this one is a quadcopter. 这是一个四轴飞行器。 It's a small model helicopter. In a way, it's a toy, no? 一个小型的直升机模型。差不多是个玩具吧。 And so this one was military technology a few years ago, and now it's open-source,

My Fellow Americans, protecting the safety and well-being of American Citizens is my highest duty as President. 我的美国同胞们，保护美国公民的安全与福祉是我作为总统的最高责任。 Yet, lawless sanctuary jurisdictions are nullifying fed

THE PRESIDENT: Good morning. For years, America's automakers have faced serious challenges -- burdensome costs, a shrinking share of the market, and declining profits. In recent months, the global fin

Last December ,I were to Boston to visit my parents. One day ,when I was skating at Boston Common , 去年十二月,我去波士顿探望我父母.有一天,当我正在波士顿公园滑冰的时候, I came to know a skating coach by the name of the Joe Toliver ,

So I decided to focus on using data and analytics to help make the most critical decision in public safety, 所以我决定将重点集中在使用数据和分析以帮助作出最关键的判断在公共安全方面， and that decision is the determination of whether, whe