The secret agent took over and his mind began to work coldly, watching for clues, for lies, for hesitations.

特工接手，他的头脑开始冷冷地运转，寻找线索，寻找谎言，寻找犹豫。

They are called natural killer cells, and you can think of natural killer cells almost like the secret service agents of your immune system.

它们被称为自然杀伤细胞，您可以将自然杀伤细胞视为免疫系统的特工。