语法与词汇 6._____about his financial situation, I would have helped him out.

【正确答案】 C

【答案解析】由题干信息和主句的“would have done”结构可知，此处是对过去事实的假设，因此条件句用“had done”结构，此结构可以省略if，将had放在句首，句子倒装。故选C。