could

I could do it, he mused..我能做这件事，他沉思着。

could be,可能是；有可能

could have,本能够；本来也可以

how could i,我怎么能；我如何能够

could have done,本来能做成的（却没做成）

nobody could,没人能做到；那么别人也休想

could not help,禁不住，忍不住

could break,可能破碎

could do with,需要；将就；能对付

could not but,不得不…

so how could i,我又怎么能够