It is _____ Tom often breaks the school rules ___

It is _____ Tom often breaks the school rules ___

It is _that____ Tom often breaks the school rules __that___ makes his teacher unsatisfied with him.
第一个that为主语从句的引导词，第二个that为强调句型“It is...that..."中的连词。追问怎么看是定语从句还是主语从句之类的如果我想到关系副词那些，是因为看成了定语从句是吗追答主语从句就是一个句子充当整个句子的主语，位置是在谓语动词之前；定语从句在先行词的后面。