?????????“???” ??????

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

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

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

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