I teach a course on applied positive interventions and we have a service learning component as a part of that class.

我教积极干预应用,课程也包括一个服务教育部分。

哈佛公开课 - 幸福课课程节选

And that group did much better on the learning task than the control group, because they were put into a positive mood.

第二组,在学习任务上比对照组表现更好，因为他们被置于积极情绪。

哈佛公开课 - 幸福课课程节选