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

2??????????

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

4???sn??

5???????

???????????????2?20????? (? ??)??20?????,???????????????,??????????????????,??

?:??,?,?,1972??7?????????????,?,??????1992??12??,1995?8????????????1992???????????????12????????2002??????????????????9?????,?;2002?9????2010?3??????,?,????;2010???3?????2013???????12?,?????????????????????????????????;2013?????12?2017??????????12?,?????????,?????????,???;2017????12??2020??????8?,?,????????????????????????????,???????;2020??8??2021???8?????????????????????,?????;2021????????????????8?,???????(???)

??:??