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?

We should think of ___old. I think we should take a break. I think we should think about our relationship over again. _____ to improve our English?A What do you think we should do B Do you think what do we should C What do you think should we D Do you think what should we do 选哪个理由 I really think we should c_ our diet . I think we should help her 对her提问 do you think {what should we do?}填啥 We should think ___ (much) of others than ourselves. --i think we should keep----inthe readying room . I think we should help her.（对her提问） I think we should meet each other in person Do you think we should ____(buy) some healthy food 英译汉We should want to national think urgent nat. what do you think ---------do to protect wildlife?A should we B we should C it we shouldD it is we should 为什么选B 不选A do you think should we=do you think if weshould how do you think we should...的how do you think 是询问看法吗? （同义句）We should think about where we can hold the charity show.We should think about ______ hold the charity show.（汉译英）情绪_______ ______ to improve our environment?A.What do you think we should do B.Do y______ to improve our environment?A.What do you think we should do B.Do you think what we should doC.What do you think should we do D.Do you think what should we do