某一经济活动存在负的外部经济效果是指该活动的（ ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='31437' and id < 2520155 and id<>'2520155' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='31437' and id > 2520155 and id<>'2520155' order by id asc limit 5