It was like the off-track betting system.

这有点像场外下注。

斯坦福公开课 - 经济学课程节选

So, these memory cells are a way that your immune system keeps track of antigens that it's been exposed to for even if maybe the plasma cells that were producing antibody in response to the initial exposure have died and disappeared.

所以,这些记忆细胞,是人体免疫系统记忆抗原的一种方法,即使由浆细胞产生的抗体,在初次免疫应答中全部被消灭,记忆细胞仍然能迅速分化为抗体分泌细胞

耶鲁公开课 - 生物医学工程探索课程节选