We should think about what we can do ____________ (keep) animals and plants from becoming endangered.

问题描述:

We should think about what we can do ____________ (keep) animals and plants from becoming endangered.
用所给动词的适当形式填空.答案是to keep,我想知道为什么加to啊?

答案:to keep
语法:不定式表目的
翻译:我们应该想想要做点什么来(为了)预防动植物的灭绝.
例句:Chinses government take many active measures to overcome financial crisis.中国*采取了很多积极措施来克服经济危机.