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

2???????

3???????????

4????????

5?????600

???????(???????????????):6??????17??????????30??????????????,??????,53%??????

????,??????????3.31?????????,?????????“??”?“?????”???????“??????”??4.8??????,??????????12.8????,??1978??????????????5.05%?????????13.84%?????????4??,??????????????????515??1000???????????,?????????????,2019???????????????????2000???40%???,????????,4.5????????????????

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

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