When we do experiments, each group of three has an experimental setup to measure the phenomenon.

当我们做实验的时候，每个三人小组建立实验设备,来测量观察的现象。

麻省理工公开课 - 媒体、教育、市场课程节选

And we group the students into subgroups at that table, three students in a group.

我们再将一桌学生分成更小的组,三人一组。

麻省理工公开课 - 媒体、教育、市场课程节选