Question

6．If I had been more careful，the failurecould have been avoided．（avoid）
如果我更细心些，这次失败就能避免了．

Answer 1

分析 could have been avoided

解答 答案：could have been avoided．
本句是对过去事实的虚拟，从句用had done，主句用could/should/might have done，failure与avoid之间为逻辑上的被动关系，所以用被动结构；故答案为could have been avoided．

点评 虚拟语气的用法：1．对现在的虚拟：if+过去式，主句：would （should，might，could ）+do；
2．对过去的虚拟：if+过去完成式，主句：would （ should，might，could ）+have done；
3．对将来的虚拟_：if+did/were to do/should do，主句：would （should，might，could ）+do．