向一瓶酒精溶液中误加入80克的水后，需要再加人20克纯酒精才能恢复成原浓度，则 原酒精溶液的浓度为

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SQL Error: select id,body,options from ***_enewstiku where sourceid='31379' and id < 2516887 and id<>'2516887' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='31379' and id > 2516887 and id<>'2516887' order by id asc limit 5