Mr Li said that that that that that student used in the object clause could be omitted.第一个that作为关联词引导said的宾语从句.第二、三个that,即that that表示“那个that“,前面的that是指示代词,后面的that是名词,就是“that”这个单词.第四个that,是关联词,引导定语从句,修饰第三个that,也就是“那个that”.第五个that,是指示代词,that student那个学生.翻译：李先生说,那个学生（that student）用在宾语从句中的那个that (that that)可以省略.