I ________ have written to him because he phoned me shortly afterwards.
I ________ have written to him because he phoned me shortly afterwards.
A.ought to
B.must
C.couldn't
D.needn't
答案及解析: D
I ________ have written to him because he phoned me shortly afterwards.
A.ought to
B.must
C.couldn't
D.needn't
答案及解析: D