查询选课表elective中选修了各门课程（课程编号的字段名为cno) 的学生人数、总分、平均分、最高分、最低分。（学号字段名为sno)。

A.（1）处填：proc

B.（2）处填：avg(成绩)

C.（3）处填：课程号=@cn

D.（4）处填：pcd '3-105'

A.SELCET 课程号,MIN(成绩) FROM 选课表 GROUP BY 课程号;

B.SELCET 课程号,SUM(成绩),FROM 选课表 GROUP BY 课程号;

C.SELCET 课程号,MAX(成绩),MIN(成绩),AVERAGE(成绩) FROM 选课表 GROUP BY 课程号;

D.SELCET 课程号, MAX(成绩), FROM 选课表 GROUP BY 课程号;

A.SELCET 课程号, AVG(成绩) FROM 选课表 ORDER BY 课程号

B.SELCET 课程号, MAX(成绩) FROM 选课表 GROUP BY 课程号

C.SELCET 课程号, MIN(成绩) FROM 选课表 GROUP BY 课程号

D.SELCET 课程号, SUM(成绩) FROM 选课表 GROUP BY 课程号

A.SELCET 课程号, AVG(成绩) FROM 选课表 ORDER BY 课程号

B.SELCET 课程号, MAX(成绩) FROM 选课表 GROUP BY 课程号

C.SELCET 课程号, MIN(成绩) FROM 选课表 GROUP BY 课程号

D.SELCET 课程号, SUM(成绩) FROM 选课表 GROUP BY 课程号

A.SELCET 课程号, AVG(成绩) FROM 选课表 ORDER BY 课程号

B.SELCET 课程号, MAX(成绩) FROM 选课表 GROUP BY 课程号

C.SELCET 课程号, MIN(成绩) FROM 选课表 GROUP BY 课程号

D.SELCET 课程号, SUM(成绩) FROM 选课表 GROUP BY 课程号