A studio of three hours' lecture in a large lecture hall, and two hours of recitation in groups of thirty.

在一个大的讲堂的教室里,讲三个小时讲座，并以三十人为一组,进行两小时背诵。

麻省理工公开课 - 媒体、教育、市场课程节选

so you can see that there is going to be two sets in antibonding, three sets in bonding for a net of one, giving us the single bond.

因此你能看到,反键轨道上有两组，三组成键，得到一组净成键，所以成的是单键。

麻省理工公开课 - 固态化学导论课程节选

You take two groups of kids and you ask them to do something like draw pictures.

你找来两组小孩,叫他们做一件事，例如画画。

耶鲁公开课 - 心理学导论课程节选