问题
选择题
28. ---- Who told you my email address?
---- I don’t remember clearly. It _______ Karen.
---- It _______ Karen. She doesn’t know my email address.
A．may have been; can’t have been
B．must have been; mustn’t have been
C．may have been; must have been
D．must have been; mustn’t be
答案
A。
根据题意“I don’t remember”可知第一空是要表达“可能是Karen
的）”；又根据“She doesn’t know my email address. ”可知说话人认为“不可能是Karen.”.