American Mort Schechter was a tail-gunner with the 467th bomb group, based in Rackheath,England, and he flew on D-Day.

VOA: standard.2009.06.02

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