问题补充：
---I beg your pardon?
---Your mind must be when I was speaking, wasn’t it?
A. wondering
B. wandering
C. walking
D. speaking
答案：
A. wondering
(答案→)B. wandering
C. walking
D. speaking
解析：考查词义辨析。wonder 想知道，wander徘徊，walk步行，speak说话，句意：你再说一遍？当我说话的时候，你的大脑一定走神了，对不对？故选B。
