By the end of each week,the students take a quiz,hand in their homework,which are assessed by their peers under the supervision of the instructors,get a grade, move to the next week. 每周结束的时候，学生们参加一个测验

THE PRESIDENT: Good morning, everybody. I just had a very productive meeting with two members of my Economic Recovery Advisory Board: Paul Volcker, who's the former chair of the Federal Reserve Board;

Something called the Danish Twin Study 一个叫“丹麦双胞胎”的研究表明， established that only about 10 percent 普通人在生物学允许的限度内的寿命， of how long the average person lives, 仅仅有百分之十 within certain biological limits, is dict

Easter is a moment to reflect and an important time for Christians and others to gather together with families and friends. This year, after a period of intense debate over the right future for our co

You know, I always wonder, who makes up those rules? 我一直都挺郁闷的，到底是谁制定这样的臭规定啊？ For years I went to -- Look, I went the Harvard Ed School. I thought I knew something. 多年以来，我一直会去哈佛的Ed学校。我想我还是了解一些情况的。 They