英语时态：The official stamp showed that my documents are valid.为什么show用过去式,后面却用are?
问题描述：
英语时态：The official stamp showed that my documents are valid.为什么show用过去式,后面却用are?
为什么不是这样：
The official stamp shows that my documents are valid.
The official stamp showed that my documents were valid.
答
在你看到文件之前,official stamp (公章或邮戳）肯定是已经盖在了文件上,所以要用过去式showed.另外,文件有效指的是一种恒常的状态,状态是可以一直持续的,况且,是阅读后看后才知道文件是否有效.一般来说,主句用了过...