查询各科成绩最高分、最低分和平均分:以如下形式显示:课程ID,课程name,最高分,最低分,平均分,及格率,中等率,优良率,优秀率 --及格为>=60,中等为:70-80,优良为:80-90,优秀为:>=90 (超级重点) SELECT s.c_id as "课程ID",c.c_name as "课程name" ,MAX(s.s_score) AS "最高分" ,MIN(s.s_score) AS "最低分" ,ROUND(AVG(s.s_score),2) AS "平均分" ,RO...