???????????????????????????????????????????????,????????????????????,???,??????????????,?????????
???????????????,????,????????????(??????????????????????? ??????????????? ????????? ??????)
???:?????
????3???????
??????:??????????
????????????16??????
???????:????????“???”
????????????:?????
???????!??????20???????
???????5?????:????????
??????GM??:???????????
??????????????12???
??????10???6????4??????
??:???????????????????
??????????????????????
????????????:???????
?????????????????????
??????:??2??6??????????
????????:????????????
???COS??????????:?????
??????0.7%???0.8%
“???”?“???”,?????????????
???????????????????
?????????????????7???
??????????????2000?????
????????????:????????????
????????:????????????
?????????????????7???