Living organisms are constantly in contact with pathogens which, under the proper conditions, are able to parasitically proliferate to create pathological conditions.
活的生物体是在与病原体接触不断，在适当的条件下，能够寄生繁殖创造病理状态。
2
He would court opprobrium if he were to argue that, as a class of human beings, they lack morals or self-control, or to claim that they exist parasitically on the hard work of others.