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

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

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

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

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