The reason for that complexity is because your immune system needs to be able to respond to all the potential foreign invaders that we could encounter.

整个系统之所以如此复杂是因为,免疫系统需要应对所有,我们要面对的来犯之敌

耶鲁公开课 - 生物医学工程探索课程节选

Because it's working to defend us against many different kinds of potential assaults, the immune system has a diverse repertoire of responses that it uses in the face of these assaults.

免疫系统的工作就是抵御,不同种类的潜在威胁,免疫系统具备类型众多的免疫反应类型,以应对各种威胁

耶鲁公开课 - 生物医学工程探索课程节选