A
SELECT cname,teacher FROM S,SC WHERE S.s#=SC.s# AND s#='95020'
B
SELECT cname,teacher FROM S,SC,C WHERE S.s#=SC.s# AND SC.c#=C.c# AND s#='95020'
C
SELECT cname,teacher FROM SC,C WHERE SC.c#=C.c# AND s#='95020'
D
SELECT cname,teacher FROM S,SC,C WHERE s#='95020'
