??????“???” ?????????

?????2??18??? (????????????????????? ???)????????18????,???????????,????????????“?????????????”,????????????????????????????????,??“???????????”??,???????????????,?????????????

??“???????????????”?????????????????,??????????????,?????????,?50??????????????(???)?????,??500??,??????????????????1-3???????????,??????0.3%-0.5%/?????????????????????,????????????????????????????????????????????,????????,??,???????,??

???,“??????”??????????????????????,???????????,?????,??20??(???)?????0.3%/?????????????,20?????0.5%/?????????????????????????????????????????????????

??????????????,???????“???”??20??(?)???????????,????20???,????????????????,????????????????????????(??????????) ??????:???????