1）根据表查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩2）根据表查询在 SC 表存在成绩的学生信息实验数据：学生表：create table Student(Sid varchar(6), Sname varchar(10), Sage datetime, Ssex varchar(10));insert into Student values(''01'' , ''赵雷'' , ''1990-01-01'' , ''男'');insert into Student values(''02'' , ''钱电'' , ''1990-12-21'' , ''男'');insert into Student values(''03'' , ''孙风'' , ''1990-05-20'' , ''男'');insert into Student values(''04'' , ''李云'' , ''1990-08-06'' , ''男'');insert into Student values(''05'' , ''周梅'' , ''1991-12-01'' , ''女'');insert into Student values(''06'' , ''吴兰'' , ''1992-03-01'' , ''女'');insert into Student values(''07'' , ''郑竹'' , ''1989-07-01'' , ''女'');insert into Student values(''08'' , ''王菊'' , ''1990-01-20'' , ''女'')?成绩表create table SC(Sid varchar(10),Cid varchar(10), score decimal(18,1));insert into SC values(''01'' , ''01'' , 80);insert into SC values(''01'' , ''02'' , 90);insert into SC values(''01'' , ''03'' , 99);insert into SC values(''02'' , ''01'' , 70);insert into SC values(''02'' , ''02'' , 60);insert into SC values(''02'' , ''03'' , 80);insert into SC values(''03'' , ''01'' , 80);insert into SC values(''03'' , ''02'' , 80);insert into SC values(''03'' , ''03'' , 80);insert into SC values(''04'' , ''01'' , 50);insert into SC values(''04'' , ''02'' , 30);insert into SC values(''04'' , ''03'' , 20);insert into SC values(''05'' , ''01'' , 76);insert into SC values(''05'' , ''02'' , 87);insert into SC values(''06'' , ''01'' , 31);insert into SC values(''06'' , ''03'' , 34);insert into SC values(''07'' , ''02'' , 89);insert into SC values(''07'' , ''03'' , 98)?课程表create table Course(Cid varchar(10),Cname varchar(10),Tid varchar(10));insert into Course values(''01'' , ''语文'' , ''02'');insert into Course values(''02'' , ''数学'' , ''01'');insert into Course values(''03'' , ''英语'' , ''03'')?教师表create table Teacher(Tid varchar(10),Tname varchar(10));insert into Teacher values(''01'' , ''张三'');insert into Teacher values(''02'' , ''李四'');insert into Teacher values(''03'' , ''王五'')