There was also the question of the four million former slaves.

VOA: special.2010.01.14

So, you should know that there's four radial nodes, right, we have 5 minus 1 minus l -- is there a question?

你们要记住这里有四个节点，对吧，５减去１减去ｌ，有问题吗？

麻省理工公开课 - 化学原理课程节选

That's four items. Show up, sit down, and the first question is does anybody have a pen?

总共4件东西，你们来到，坐下，第一个问题是你们有带铅笔吗？

麻省理工公开课 - 固态化学导论课程节选

So this is what he asked them to do: Select four answers to the question 'What should a reader be to be a good reader?' "The reader should belong to a book club."

这就是他要求学生们做的：,从以下四个选项中选取问题,“读者如何才能成为好读者”的答案：,“读者应该是书友会的成员“

耶鲁公开课 - 1945年后的美国小说课程节选

Now think of another product in American history that doubled every decade for four decades, and then imagine that that product became the country's, without question, absolute largest export.

思考下在美国历史中有没有另一种产品曾,有如此辉煌的成就,那么这个产品将毫无疑问地,成为美国最大的出口产品

耶鲁公开课 - 美国内战与重建课程节选