Now take these two fingers-- the middle finger and the thumb-- and as much as possible, from that 90 degree angle, create a circle.

再让这两个手指-,中指和姆指-,尽可能保持直角时围成一个圆圈。

哈佛公开课 - 幸福课课程节选

Middle finger exactly and your thumb.

中指和姆指。

哈佛公开课 - 幸福课课程节选

So-- if you don't feel comfortable doing it, don't do it-- what I'd like to do now is as following: Take your thumb and your middle finger and create as much as possible a 90 degree angle.

感觉不舒服的，就不要做，希望按下面的指示做：,让你的姆指和中指,尽可能形成一个直角。

哈佛公开课 - 幸福课课程节选