One way to mark time is to imagine it carries a clock as it moves, and put markers every second.

标记时间的一种方法是,想像它带着时钟运动,并且每秒做一次标记

耶鲁公开课 - 基础物理课程节选

These cells can now kill cells that have the correct signature, and the signature is MHC-1 with this foreign antigen associated with it.

而这些细胞现在可以杀伤带标记的细胞,这些标记就是MHC-1表面受体,和与其相联的异己抗原

耶鲁公开课 - 生物医学工程探索课程节选