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

2????????

3??????????

4?????cs

5??????

????12???20??????????? (?? ?????????????)?20?,??????????12?????????19??????????,????????400.4??,?????23%?

12????19?,??? ?? ?????

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??????????????????????????,?????????????,???????????????1????????1?11?27????,??????????????40??????????500.8???????,??????????500??????????????????,??????????????,?????????????????????????

??????????????????,???????“???????????????????????????????????????”??,????????????????,???????????,??????,???????????????????,??????????,?????????????(???????)

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