For example, that embryo that I showed on one of the first slides where there's clearly a head region and a tail region.

比如我在第一张幻灯片里展示的那种胚胎,已经有了明显的头部和尾部

耶鲁公开课 - 生物医学工程探索课程节选

There's a region that looks the head, and a region that looks more like the tail.

有一个区域看起来像头,另一个区域看起来像尾

耶鲁公开课 - 生物医学工程探索课程节选