问题补充：
-----Where did you find your wallet?
-----It was in the park we went for a walk yesterday.
A. where
B. that
C. how
D. Which
答案：
(答案→)A. where
B. that
C. how
D. Which
解析：考查强调句的省略结构。该句为强调句，完整的句子为 It was in the park where we went for a walk yesterday that I found my wallet.
