Meng Peij ie，an ordinary girl who was among the 10 people awarded the title of “Touching China 2011”，must be both optimistic and strong-minded. Otherwise, she _______ her disabled adoptive mother for 12 years.
A.mustn't have looked after
B.can't have looked after
C.couldn't have been looking after
D.shouldn't have looked after
网友回答
C解析本题考查虚拟语气。结合后半句句意“否则，她不可能照顾她残疾的养母12年”可知此处是与过去相反的虚拟语气。