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???????2???18?? (? ??)??18??,???????????????????,????????????????“??”,???????????????,???????“??????”????????????,??,???????????
?????????“??”??????????????????,???????????????????????????,????,?50?????(?????????)???,??500???????????????,????????1-3?,???0.3%-0.5%/?????????,?????????????,?????,?????,??,???????
???,“???????????????”?????????????????????????,????????????????,??????????????????,???20??(????????????)?????????????????????0.3%/?,20???0.5%/????????????????????????????????????????????????????
?????????????,???“???”???????????20???(???)???????????,???20????????,??????????,????????????????????????????????????????????????????????????????????????????????(??) ???????????????:???
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