● RELATION S (S#DOMAIN S#, NAME DOMAIN NAME,AGE DOMAIN AGE,SEX DOMAIN SEX)KEY (S#); RELATION C (C#DOMAIN C#,FOMMAT DOMAIN A1, TEACHER DOMAIN NAME,OFFICE DOMAIN A2)KEY (C#): RELAT I ON S0(S# DOMAIN S#,C# DOMA IN C# GRADE DOMAIN GRADE)KEY (S#,C#); 188188 RELATION S（S# DOMAIN S#， NAME DOMAIN NAME，AGE DOMAIN AGE，SEX DOMAIN SEX）KEY（S#）； RELATION C（C# DOMAIN C#，FOMMAT DOMAIN A1， TEACHER DOMAIN NAME，OFFICE DOMAIN A2）KEY（C#）; RELATION SC（ S# DOMAIN S#，C# DOMAIN C# GRADE DOMAIN GRADE）KEY （S#，C#）;