单选题 When I saw the vase in the shop window, I knew it was exactly what I ______.
A. look for B. am looking for
C. had been looking for D. have looked for

【正确答案】 C
【答案解析】[解析] 当我在橱窗里看到这个花瓶的时候，就断定这就是我一直寻找的那个。根据句意，说话人现在找着了花瓶，因此找花瓶这个动作成了过去一段时间持续的动作，故选C。