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

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

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

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

??

??:???????????,??????????,??????????????