数列{an}是等差数列S9=18,Sn=240,an-4=30(n>9),则n的 发布时间:2017-05-02 19:03 │ 来源:www.tikuol.com 题型:填空题 问题: 数列{an}是等差数列S9=18,Sn=240,an-4=30(n>9),则n的值为 ______.
题型:填空题 —Will you be on holiday soon? —Well, I'm too busy to take a holiday now. I'll be able to take _______ or two months from now. [ ]A. this B. that C. it D. one 查看答案