C 意思是 直到很晚他才意识到已经很晚了，改回家了也就是说很晚的时候他才意识到/或者说 “他没有意识到”这个动作一直发生，直到“很晚”了才结束这是强调句，还原之后应该是 He hadn't realized it was too late to return home until it was dark 强调的时候把not 和until提前也可以说成It was until dark that he hadn't(didn't) realized it was too late to return home但很少有人这么说...
此题选C首先看B的错误：Hardly不是Never, only那些可以前置，然后把句子改成倒装句的词。能引起倒装的还有seldom, scarcely, hardly, not only ..... but also, at no times, not until, under no circumstances, no sooner .......
选B查 no sooner than / hardly when /not... until 这几个句型的用法。1、no sooner had she said it than she burst into tears.2、hardly had we sat down at the table when the phone rang.3、...
