As Amherst College biologist Paul Ewald observes, the bugs that cause AIDS, tuberculosis, typhus and measles all reached us through animals

• 据安赫斯特学院生物学家保罗·艾沃德观察，引起艾滋病、结核病、斑疹伤寒、麻疹的病原体都是通过动物传给我们的。