A virus presently located in a remote rain forest could, by means of air travel, be in a major city by this time tomorrow. We now live in such crowded cities that the scope for transmission of a virus which travels through air is greater than ever

A virus presently located in a remote rain forest could, by means of air travel, be in a major city by this time tomorrow. We now live in such crowded cities that the scope for transmission of a virus which travels through air is greater than ever before.

我们现在生活的城市人口这么拥挤，病毒在空中传播的范围比以往任何时候都要大得多。(考点:“travel"须译为“传播”;主句“we now live in such crowded cities”改译为主题句;“such...that..."结构不宜直译为“如此...以至于”)