????????????? ????99.9%??

????????2??21????????? ???????????????:???????2????20????,????????????,??????????????????,????99.9%???????????,0.1%????????????????????????????????????????????

???????????????????????????????????????

?????????????,?,??????????????,???????????,?????????????,???????????????,????

???«?????????????»??????,??“???????????”?,???,??,??????????????,???????????????????????????

???????,???????(?????????????) ???????????:?????