She showed me a red silk dress online which cost her only 10 dollars.A. to be boughtB. b

问题补充：

She showed me a red silk dress online, which cost her only 10 dollars.

A. to be bought

B. being bought

C. bought

D. having bought

答案：

A. to be bought

B. being bought

(答案→)C. bought

D. having bought

解析：考查非谓语动词。过去分词bought作定语，修饰red silk dress，表被动关系，选C。