请问英语同位语从句!有个题：---- was known to them that Bob had broken his

第一个that引导的从句,既不是定语从句,也不是同位语从句,而是主语从句,it 这里是形式主语,真正的主语是that Bob had broken his promise。。。第二个that引导的从句,是同位语从句,是对promise的进一步说明,同位语从句和定语从句的区别,就是看引导词that是否在从句中充当成分,定语从句中,that是关系代词,在从句中充当主语或宾语的成分,比如：Bob broke his promise that he had made last week。在这个从句中,he had made last week不是一个完整的句子,缺少宾语,that在从句就充当宾语的成分,相当于：he had made the promise（用that 替代）last week。因此这个句子就是定语从句,这里的that可以省略。而同位语从句中,that在从句中不担任任何成份,只起连词作用,但又不能省略。我们再回来看这个句子,he would give them a rise（他要给他们升职）这就是一个主语（he)、谓语(would give) 、宾语(them 间接宾语、a rise直接宾语）都齐全的完整的句子,所以这不是定语从句,而是同位语从句。