下面一题是 2008 山东卷的高考题：

Thank you for all your hard work last week. I don’t think we _______ it without you.

A. can manage

B. could have managed

C. could manage

D. can have managed

记得前不久有位网友问过相似的问题，也是问 last week 的句子成分问题，当时有老师说它是定语，也有老师说它是状语，但我还是不明白。请各位专家分析指导，谢谢！