Nobody could save him even though Hua Tuo should come here 中could能不能换成can 如果不能 为什么

Nobody could save him even though Hua Tuo should come here 中could能不能换成can 如果不能 为什么 Nobody could ever replace Nobody could ever replace you Nobody could ever replace you nobody could ever replace you nobody could erer replace you Nobody could ever replace you.啥意思? Nobody could ever replace you为什么用could不用can The doctor did what he could （to save）the child.为什么是to save?而不是是save? he could do nothing to save it 中文意思 could not save session variables(2) 这是什么内容 火星上有外星人?nobody could answer it! NOBODY COULD SEE THE SUIT的中文是什么意思? Nobody could given the correct answer,______?就是反义疑问句. nobody could learn to swimming without jump into save save save