I don’t remember when and where I this umbrella.A. buyB. have bought C. will buyD. bought

问题补充：

I don’t remember when and where I this umbrella.

A. buy

B. have bought

C. will buy

D. bought

答案：

A. buy

B. have bought

C. will buy

(答案→)D. bought

解析：通过情景来判断时态，根据句意“我记不住是在何时何地买的这把雨伞”可知用一般过去时。