[解析]
(1)B.细节理解题.根据第一段One fine afternoon,I was walking along Fifth Street when I remembered that it was necessary to buy a pair of socks可知作者想买一双袜子.故选B.
(2)D.细节理解题.根据第二段 I had no idea of that,as my entrance had been accidental 可知作者进入这家店是偶然的.故选D.
(3)C.推理判断题.根据最后一段if you can keep this up,if this is not merely from having a new job,if you can keep up this high spirit and excitement day after day,in ten years you will own every sock in the United States可知作者在最后一段中所说的意思是说如果你对工作保持浓厚的兴趣,你将来会成功的.故选C.