And obviously there's been tremendous practical applications associated with this world -- things like the eradication of smallpox, the advent of a vaccine against cervical cancer, which we now know is mostly caused by human papillomavirus.
而且显然已经出现了无数有关病毒的 切实应用在这个世界上 -- 像天花的根除， 子宫癌的疫苗的降临-- 我们现在知道它大部分是由乳头瘤病毒引起的。