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

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

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

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

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