已知一个等差数列共有2n+1项,其中奇数项之和为290,偶数项之和为261,则第 发布时间:2017-04-28 21:50 │ 来源:www.tikuol.com 题型:选择题 问题: 已知一个等差数列共有2n+1项,其中奇数项之和为290,偶数项之和为261,则第n+1项为( )A.30B.29C.28D.27
题型:选择题 用给单词的适当形式填空。1. How much _____ (be) these things? 2. He can _____ (do) Chinese Kung Fu.3. I like this movie. The movie is very _____ (interest).4. My sister _____ (not like) tennis. 5. Can you help kids with _____ (swim)? 查看答案