A.
select * from student,course,sc where sudent.sid=sc.sid and course.cid=sc.sid
B.
select sid,sname,depart,zhuanye,cid,cname,grade from student,course,sc where student.sid=sc.sid and course.cid=sc.sid
C.
select student.sid,sname,depart,zhuanye,cid,cname,gradefrom student,course,sc where student.sid=sc.sid and course.cid=sc.sid
D.
select student.sid,sname,depart,zhuanye,course.cid,cname,gradefrom student,course,sc where student.sid=sc.sid and course.cid=sc.sid