1.But that he saw it,he( )it.A could not have believed B did not believe C could not believe D can not believe,从句是一般过去时,主句不应该是过去将来时吗?那这么选A呢?2.He must have an accident ,or he ( )here then.A should have been B should beC would be D were主句是过去将来时,那么从句应该是一般过去时或者过去将来时,怎么是A
问题描述：
1.But that he saw it,he( )it.
A could not have believed B did not believe
C could not believe D can not believe
,从句是一般过去时,主句不应该是过去将来时吗?那这么选A呢?
2.He must have an accident ,or he ( )here then.
A should have been B should be
C would be D were
主句是过去将来时,那么从句应该是一般过去时或者过去将来时,怎么是A
答
“要不是他亲眼所见，他绝不可能相信这件事。”用过去将来时是因为他确实已经相信了。 could not have 不可能已经 “But that”接句子 “but for” 接名词，要不是……
“他一定是出了什么事，要不然他应该已经到这了。”
should have been 本该做某事而实际上没做。他本该到达而实际上没到。
多做点虚拟语气的题你就会有感觉的了。
答
could not have done 是本不应该做而做了
should have done 是本应该怎样的意思
答
做虚拟语气的题不能这样分析的.
主要是要掌握怎样的表达是表达什么意思.
could not have done 是本不应该做而做了 意思刚好对.
should have done 是本应该怎样的意思.最主要的是要记住一些固定的语法.而不是死背该用什么时态.