【题目】Believe it or not, it was the fifth time that I the song Yesterday Once More in public.
A.sing
B.have sung
C.had sung
D.sang

【答案】C
【解析】句意：信不信由你，这是我第五次当众唱Yesterday Once More这首歌。This / That/ It is/ was＋the＋序数词＋名词＋从句(从句中的时态要用完成时态；如前为is，则用现在完成时，如为was则用过去完成时)，故选C。