单选题 A: The door was open.
B: It ______ open. I had locked it myself and the key was in my pocket.
  • A. can't be
  • B. mustn't be
  • C. can't have been
  • D. mustn't have been


【正确答案】 C
【答案解析】此题考查对过去发生的事情的否定推测。对过去的否定推测只能用can't have done 的形式，与对过去的肯定推测must have done相对应。根据该题题干，时间上针对过去，所以选C。