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) of the examination results, all separated by commas or spaces student achievement, and then the results for the class descending order, requirement that sort the results, and the results were statistically class given less than 60 minutes, 60 segments, 70 segments, 80 segments and 90 sub-class of each section, and the average number of points.