But personal DNA machines can also save human lives. 但个人DNA检测器还可以挽救人类的生命。 Professor Ian Goodfellow is a virologist at the University of Cambridge. Ian Goodfellow教授是剑桥大学的病毒学家。 Last year he traveled to
June 20, 2007 2:39 P.M. EDT THE PRESIDENT: Welcome. I'm glad you're here. America is a nation that leads the world in science and technology. Our innovative spirit is making possible incredible advanc
But something strikes you when you move to America and travel around the world: 但搬到美国后，有些事使我印象深刻： Every education system on Earth has the same hierarchy of subjects. Every one. 如果你周游世界，你会发现每个国家的教育体系都存
