单选题 If I______run out of ink, I would have finished writing the paper.
[A] haven't [B] shouldn't [C] hadn't

【正确答案】 C
【答案解析】[句意] 如果我的墨水没用完，我就会写完这篇论文。本题考查的是虚拟语气。因为主句是现在完成时态，根据虚拟语气的谓语结构，条件从句中的谓语一定是过去完成时态，故选项[C]正确。