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???????2?17???????? (???????? ?????)????17????????????????,??,2??????????13??16??????????,????????????????????????????,?????????????72?????????????????15.3?,????????????;????????10???????48?6.5?~10.9????,?;??????????????????4???
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?????????2??18??2??22??????????,???????????,????????????,??????2?19?2??20???,?????????????,??????????????????????,????????,???,???(???)
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