人体通过晒太阳来合成维生素D，可是皮肤科医生理查德·威勒指出，阳光还可以带来另一个惊人的益处。他的团队通过新研究表明：一氧化氮这种大量储存在皮肤中的化学传递质，能通过紫外线照射而释放出来，对血压和心血管系统产生很大益处。这是什么意思呢？那好，就从解释为什么苏格兰人比澳大利亚人更容易生病开始吧……演讲视频（无字幕）：Richard W
Hi, everybody. 大家好。 On behalf of all the Obamas-Michelle, Malia, Sasha, Bo, and the newest member of our family, Sunny-I want to wish you a happy and healthy Thanksgiving. 我谨代表米歇尔、玛莉亚、萨莎、波以及我们的新成员萨尼这些
THE PRESIDENT: Madam Speaker, Vice President Biden, members of Congress, distinguished guests, and fellow Americans: Our Constitution declares that from time to time, the President shall give to Congr
Hello, class of 2015. I am so honored to be here today. Dean Khurana, faculty, parents and most especially graduating students. 2015届毕业生你们好。今天我很荣幸地站在这里。迪恩库拉纳，教职员工，家长们，尤其是你们毕业生们。 Thank you so much for
