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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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