We shall appreciate this difficulty more clearly, by looking to certain existing faunas and floras.

通过观察某些现存的动物群和植物群，我们就能更清楚地了解这种困难了。

youdao

We shall appreciate this difficulty more clearly, by looking to certain existing faunas and floras.

通过观察某些现存的动物群和植物群，我们就能更清楚地了解这种困难了。

youdao