下面的段落中的主题句,段落推展句和结论句分别是什么? (1)To be an educated person is not easy. (2)Firstly we should know clearly the purpose of being educated. (3)Secondly, we should be diligent and persistent, trying our best to overcome all the difficulties that we come across. (4)Lastly, we should not only educate ourselves, but also help others as much as possible to acquire knowledge and skills. (5)Generally speaking, an educated person will have more responsibility for his country and the society.