And importantly, those bits of DNA are passed on to the cells' progeny, so cells are protected from viruses not only in one generation, but over many generations of cells.
而且重要的是，这些片段DNA 会遗传到细胞的后代， 所以细胞不只有一代会 一直被保护不受病毒感染， 好几代的细胞都会如此。