黑火药是中国古代四大发明之一 ，其主要成分是硝酸钾，S，C。

A.GRANT GRADE ON SC TO Kate

B.GRANT UPDATE ON SC TO Kate

C.GRANT UPDATE (GRADE) ON SC TO Kate

D.GRANT UPDATE ON SC (GRADE) TO Kate

A.ПSNAME, GRADE (σCNAME=’数据库技术’(C) ¥SC ¥ПSNO, SNAME (S) )###SXB###B.ПSNAME, GRADE (σCNAME=’数据库技术’(C) ¥ SC ¥ S)###SXB###C.ПSNAME, GRADE (C ¥ SC ¥ SC)###SXB###D.ПSNAME, GRADE (σCNAME=’数据库技术’ (ПCNO, CNAME (C)) ¥ПSNO, CNO, GRADE (SC) ¥ПSNO, SNAME (S) )

A.SELECT 学号, 姓名, 课程名, 成绩 FROM s, c, sc WHERE s.学号=sc.学号 AND sc.学号=c.学号;

B.SELECT 学号, 姓名, 课程名, 成绩 FROM s INNER JOIN sc ON s.学号=sc.学号 INNER JOIN c ON sc.课程号=c.课程号;

C.SELECT s.学号, 姓名, 课程名, 成绩 FROM s INNER JOIN sc INNER JOIN c ON s.学号=sc.学号 ON sc.课程号=c.课程号;

D.SELECT s.学号, 姓名, 课程名, 成绩 FROM s INNER JOIN sc ON s.学号=sc.学号 INNER JOIN c ON sc.课程号=c.课程号;

A.SELECT SNO,SN FROM S WHERE SNO NOT IN (SELECT SNO FROM SC WHERE CNO='C02' OR CNO='C04');###SXB###B.SELECT SNO,SN FROM S WHERE NOT EXISTS (SELECT * FROM SC WHERE (CNO='C02' OR CNO='C04') AND SC.SNO=S.SNO);###SXB###C.SELECT SNO,SN FROM S WHERE NOT EXISTS(SELECT * FROM SC WHERE CNO='C02' AND SC.SNO=S.SNO) AND NOT EXISTS (SELECT * FROM SC WHERE CNO='C04' AND SC.SNO=S.SNO);###SXB###D.SELECT DISTINCT S.SNO,SN FROM S,SC WHERE SC.SNO=S.SNO AND CNO<&

A.皂苷类成分

B.生物碱类成分

C.蒽醌类成分

D.挥发油类成分

A.ab0

B.a0b01

C.a0b0a

D.bc10