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

2?????????????

3?????????

4??????

5????????

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

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

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

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