If you tap somebody on the knee, your leg will jump out.

如果你轻击某人的膝盖,小腿就会弹出去

耶鲁公开课 - 心理学导论课程节选

So if you have a bad heart, then a scientist can take like, cells from your leg,

所以，如果你心脏不好，科学家就可以从你的腿上提取干细胞，

关于干细胞的研究 - SpeakingMax英语口语达人

You send the command to your leg to move.

你想要挪动双腿

耶鲁公开课 - 心理学导论课程节选