並前往https://ocw.nthu.edu.tw/ocw/upload/137/1717/%E3%80%90%E5%AF%B6%E5%A1%94%E5%80%8B%E7%B6%93%E7%A7%81%E8%97%8F%E7%AD%86%E8%A8%98%20-%20%E5%80%8B%E9%AB%94%E7%B6%93%E6%BF%9F%E5%AD%B82%E3%80%91CH09%20%20%20Cost.pdf