虚拟语气 should have done 与 could have done

问题描述:

虚拟语气 should have done 与 could have done
Five minutes earlier,we_____the last train
A,could have caught B ought to have caught 为什么选A 为什么不选B 如果有个should have caught 可以选吗 为什么

must could should would might这几个情态动词都可以用来表示对现在或者对过去的推测.但他们表示的意思是有区别的,一般情况下不可以交换使用.would 是最普通的陈述语气,如果你是客观的叙述一件事情,就可已选择这个词...