确定化合物分子量常采用的方法是

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SQL Error: select id,body,options from ***_enewstiku where sourceid='26252' and id < 2197442 and id<>'2197442' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='26252' and id > 2197442 and id<>'2197442' order by id asc limit 5