设a，b，c∈R+，若（a+b+c）（+）≥k恒成立，则k的最大值是

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15531' and id < 2638706 and id<>'2638706' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15531' and id > 2638706 and id<>'2638706' order by id asc limit 5