单选题 Where could she ______ the key? I couldn't find anywhere.
  • A. put
  • B. have put
  • C. has put
  • D. had put
【正确答案】 B
【答案解析】根据后半句“couldn't fmd”可判断，放钥匙的动作发生在“find”之前。“could have done sth．”表示“有可能(会)做某事”，是对过去发生的行为的一种推测。