I______the party much if there hadn' t been quite such a crowd of people there.
【正确答案】 C
【答案解析】解析：句意：如果没那么多人的话，我本来可以好好享受这个聚会的。这句话考的是表示与已经发生的事实相反的虚拟语气，主句had done+从句would have done。