说明：  题目：利用条件运算符的嵌套来完成此题：学习成绩>=90分的同学用A表示，60-89分之间的用B表示，60分以下的用C表示。 1.程序分析：(a>b)?a:b这是条件运算符的基本例子。
(Title: the use of nested conditional operator to complete this question: academic> = 90 points with A classmate said that 60-89 between the use of B said that the 60 points or less with C said. 1. Program analysis: (a> b)? A: b This is a conditional operator s basic example.)