could和should的区别?

问题描述:

could和should的区别?

1could主要指过去时间,表示能力,例:Two eyes can see more than one.两只眼比一只眼看得清.Could the girl read before she went to school?这女孩上学前能识字吗?2.should 1)表义务.意为“应该”(某件事宜于做)...