问题补充：
―Hello！May I speak to Jack, please?
―Yes, speaking.
－Oh, I your voice at first.
A. don’t recognize.
B. didn’t recognize.
C. hadn’t recognized.
D. haven’t recognized.
答案：
A. don’t recognize.
(答案→)B. didn’t recognize.
C. hadn’t recognized.
D. haven’t recognized.
解析：本题考查动词时态。句意为：“我”最初没有辨认出“你”的声音。说话的时候已经听出来是Jack的声音，“没听出来”是说话前的动作。所以应该用过去时态。
