a post office, I stopped some stamps.
A. Passed, buying
B. Passing, to buy
C. Having passed, buy
D. Pass, to buy
网友回答
A. Passed, buying
(答案→)B. Passing, to buy
C. Having passed, buy
D. Pass, to buy
解析：考查非谓语动词。第一空，主语I与pass之间是主谓关系，故用现在分词，在这作状语，第二空，stop to do 停下来去做另一件事，stop doing停止正在做的事，句意：通过邮局，我停下来买了一些邮票。所以选B。