等差数列{an}的前n项和为Sn，已知a3=3，a10=10，则S7的值是（  ）

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24155' and id < 2089789 and id<>'2089789' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24155' and id > 2089789 and id<>'2089789' order by id asc limit 5