he is [a good example of (the great effect we have on the lives of a great many students) ]who need access to education
词组：
a good example of ……
the great effect we have on the lives of a great many students(have effect on……)我们对很多孩子的生活的影响
who need access to education 后置定语修饰student.指需要接受教育的孩子