Who__ has common sense can believe that a dead man can come back to life

that引导的是定语从句 先行词是who时关系代词用that

Who (__ has common sense )can believe [that a dead man can come back to life]

小括号内定语从句，中括号宾语从句

所以用that，主句是who... can believe....

这热是由that引导的定语从句，修饰前面的who， 表示那些有常识的人

believe下面跟that,引寻宾语补足语