问题补充：
--- Where did you get such a beautiful skirt?
--- It was at the department store we used to shop.
A. that
B. there
C. where
D. which
答案：
A. that
B. there
(答案→)C. where
D. which
解析：考查强调句型和定语从句。本题中where we used to shop是定语从句修饰先行词store，在句子的后面还省略强调句型的后半句that I got such s beautiful skirt。句意：—你在哪里买到这么漂亮的裙子的？—就是在我们经常去购物的百货店里我买到了这个裙子。故C正确。
