????:1??????????:??????

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

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

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

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