题目

 —James should give up the idea of winning everyone’s respect and focus on his own work. —________. How did you know that? A. You are not getting it                        B. Exactly—one step at a time C. You make it sound so easy                 D. Thank you for bringing it to my attention 答案：D有一列数，第一的数为4，第二个数为7，…且从第二个数至第n-1个数，每个数是它相邻的两个数和的平均数少1，则这列数中的第n个数为 ．