题目内容：

we should think about what we can do to keep animals and plants from becoming endangered
为什么用TO KEEP

优质解答

我们应该考虑一下为了保护动植物免受灭绝我们有什么可以做的,这里的keep animals and plants from becoming endangered是我们行为所要达到的目的 所以要加to 或者in order to也是可以的