分类：教育/科学-外语学习
问题：这是一个什么句，是怎么翻译的,是如何划分句子成分的,thanks 
133.  ____ I had time, I would have run around that la again.  A. If  B. Unless  C. Had  D. When
回答：C. Had I had time, I would have run around that lake again.
虚拟语气,如果我有时间,我会再绕着湖跑
Had,have的过去式:如果,要是