????:1?2021????:???????py

2??????

3???1000?????

4????????

5??????????

????????9???13??????????????? (??????????? ???????)“?????????????????????,?????,”???????????9?12???75?????????????50????,???????????,“??????????????????50??????,??????????,????????????”

???????,????????????????????????400???????????

?????????????????????9?????12??,??,?????????????75??????????????50????????????(?????)??(????????)??????????? ???????? ? ?????

???????????,????????????????????????,???,??????:???????????????????????

?????????????????????????,??50???,??????(???????????????)???????????????????????,????????????????????,??????????????????,????

?????????(Bruce Ralston)?????????????????,??????????????????????????????????,??

?“??????????????”??????????????????????50?????????????????????“???????????”??????????????????????????,??

??????????1974????(?????????)

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