从键盘读入某班学生（人数15）的考试成绩，用逗号或空格分隔各学生成绩，然后对该班的成绩进行递减排序，要求显示排序结果，并对全班成绩进行统计，给出小于60分、60分段、70分段、80分段和90分段各段的人数以及全班的平均分数.-Reading from the keyboard into a class of students (number 15) test scores, separated by commas or spaces each student achievement, then the results of the classes conducted in descending order, requiring the display sort results, and statistics class achievement, given less than 60 points, 60 segments, 70 segments, 80 segments and 90 sub-segments and the number of each class s average score.