麻烦大家帮忙一下！！！！！！！！！！！！！！！！！！！！！！！！！

麻烦大家帮忙一下！！
use test
go
create table student
(s_id char(3) not null primary key,
name char(20),
sex char(1),
class integer,
Term integer)
go

create table course
(c_id char(4) not null primary key,
c_name char(20),
note char(20))
go
create table score
(s_id char(3) not null
references student(s_id),
c_id char(4) not null
references course(c_id),
score_val integer,
primary key(s_id,c_id))
go
insert into student values('001','Liu','M',1,2)
insert into student values('002','Zhang','F',2,1)
insert into student values('003','Li','M',3,2)
insert into student values('004','Chen','F',4,1)
go
insert into course values('1001','语文','学生成绩信息')
insert into course values('1002','数学','学生成绩信息')
insert into course values('1003','英语','学生成绩信息')
go
drop table score
insert into score values('001','1003',98)
insert into score values('004','1001',60)
insert into score values('003','1002',66)---这条语句为什么插不进呢？？
select*from score