主題:階梯地位
http://books.google.com.tw/books?id=SyODCtRb8D4C&pg=PA268&lpg=PA268&dq=%E9%9A%8E%E6%A2%AF%E5%9C%B0%E4%BD%8D%E3%80%80%E7%B5%84%E7%B9%94%E3%80%80%E9%81%8E%E5%88%86%E3%80%80%E9%87%8D%E8%A6%96&source=bl&ots=D4WItG_VeN&sig=TZO5Zu4jjFm81nB_SnVOuxT8QaU&hl=zh-TW&redir_esc=y#v=onepage&q=%E9%9A%8E%E6%A2%AF%E5%9C%B0%E4%BD%8D%E3%80%80%E7%B5%84%E7%B9%94%E3%80%80%E9%81%8E%E5%88%86%E3%80%80%E9%87%8D%E8%A6%96&f=false