°í±Þ½º·¯¿î »ö°¨¿¡ ³Ê¹« ÀÌ»Û theory ¾çÅÐÆÐµùÀÌ¿¹¿ä

±ú²ýÇÑ »óǰÀÌ¿¡¿ä^^¢½