题目

What can you see on _______  side of the river? A. another        B.others         C. other        D.the other 答案：D已知公差大于零的等差数列{an}的前n项和为Sn,且满足:a3·a4=117,a2+a5=22.(1)求数列{an}的通项公式an.(2)若数列{bn}是等差数列,且bn=,求非零常数c.