She and her family hid away for nearly 25 months before they were discovered.为什么要用hide的过去式而不是 had hidden away
问题描述：
She and her family hid away for nearly 25 months before they were discovered.为什么要用hide的过去
式而不是 had hidden away
答
have been done表示过去已经完成的 也就是现在可能已经不是这样了，所以在发现之前他们躲了25个月只是一种事实，在过去25个月确实躲了，并没有说现在已经不躲了，如果说现在不躲了 那就用have hidden away，比如she and her family have hidden away for nearly 25 months,now they are not afraid of the bad guys
答
they were discovered 她们被发现了．说明是过去时．那么hid away for nearly 25 months就更加是过去的事情了．所以要用过去时．如果两个动作紧接着发生,则常常不用过去完成时,特别是在包含before和after的复合句中...