What passes for "exposure" in the case of nonviral cancers is a combination of genes and environment and a range of other Xfactors that can vary from person to person.
就与病毒无关癌症而言，这种“暴露”包括了因人而异的基因、环境以及许多其他未知因素。
2
" If no factors other than his private opinion are considered it would follow, at least in our culture, that if he believes "X" he would publicly state "X.
如果他能不受其他因素影响的坚持自己的观念，那么至少在我们的文化习惯中，他应该公开表示“相信X”。
3
Naturally occurring radiation varies depending on factors like local geology and altitude. People are exposed to additional radiation when they get an X-ray or fly in an airplane.