???9??????????19??????????????? (??? ??)???9???????????19?????,???“?”(Sigma Geography),?????????????????????

9??19?,?“??????????????????”???????????????????? ????????????????? ???????????

?????????,???,???????????????????????,????????“????????????????”??“??????????????”“????????”“???”“?????????????????????”?,?????????????????????????????

??,“??”????????????????????????????????,???????(?)

??????????:?? ??“???????”????

?? ??“??????????????????”

????:1????????:??????

2??????????

3?????

4???????????

5??????????

???9??????????19??????????????? (??? ??)???9???????????19?????,???“?”(Sigma Geography),?????????????????????

9??19?,?“??????????????????”???????????????????? ????????????????? ???????????

?????????,???,???????????????????????,????????“????????????????”??“??????????????”“????????”“???”“?????????????????????”?,?????????????????????????????

??,“??”????????????????????????????????,???????(?)

??????????:??