问题
选择题
Though I have often heard this song _______. I have never heard you _______ it.
A．being sung, sang
B．sang, singing
C．sung, sing
D．to be sung, to sing
答案
答案：C
C。第一空填 sung，因为 song 与 sing 是被动关系；第二空填 sing，因为 you 与 sing 是主动关系。