One is a new,phone-based service for expectant mothers from Voxiva, a firm which develops interactive mobile health services.

VOA: standard.2010.02.24

First is that the ear develops from the surface layer of the embryo.

耳朵是由,胚胎的外胚层发育来了。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

And I mentioned that the ear develops from a little ball.

前面我曾说过,耳朵是由一个小小的泡囊发育而来的。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选