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

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

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

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

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