题目：
If, for any reason, you are not satisfied, simply return your purchase with your receipt for an exchange or refund within 90 days when ______ on your Sears Card or Sears Gift Card.
A) purchase
B) purchasing
C) purchased
D) purchases
答案：C
想问版友，选C是因为分词构句选pp表被动吗（因为卡片是被购买的）
谢谢