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

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

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

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

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