在这里，since的意思是：因为，引导的是原因状语从句。这句话的意思是：她不需要再考试了，因为她已经通过了。所以不能说成she need not have taken the examination again since she had already passed it，因为need not have done 意思是本不需要做而做了某事，这样整句话的意思是：因为/既然她已经通过考试了，却又考了一次，不合逻辑。...
你好。长话短说：1she did not need to take the examination again ------ 解释为：因为当时没有必要，所以就没有参加考试2 she need not have taken the examination again -----解释为：尽管当时没有必要，但还是参加了考试。...
she did not need to take the examination again since she had already passed it 意思是她没必要参加考试，于是就没参加she need not have taken the examination again since she had already passed it?...
need doing=need to be done in need 在危难中；在穷困中的 need for 对……的需要；需要…… in need of 需要…时 no need 不需要；不必了 need to do 需要做…at need 困难之时；必要时 主动用法：need to do,需要做某事被动用法：need do...
