??????“???” ?????????

????:?????????:?????????

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

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

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

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