The reason____he said that is quite clear.填关系代词还是关系副词?为什么?

问题描述:

The reason____he said that is quite clear.填关系代词还是关系副词?为什么?

关系代词/关系副词引导从句,它也要作为从句的一个成分,he said that 是完整的句子,很明显只能以副词引导.应该填why.