diff --git a/学籍管理系统步骤8.c b/学籍管理系统步骤8.c
new file mode 100644
index 0000000..a481ed9
--- /dev/null
+++ b/学籍管理系统步骤8.c
@@ -0,0 +1,170 @@
+#include<stdio.h>
+#include<string.h> 
+#include<stdlib.h> 
+int N=0;
+void menu();
+struct stu_info
+{
+	int cls,flag;
+	char name[10],num[10];
+	float maths,physics,english;
+}
+stu[20];
+void output()
+{
+	int i;
+	for(i=0;i<N;i++)
+	printf("%s %d %s %.1f %.1f %.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].maths,stu[i].physics,stu[i].english);
+}
+void sort(struct stu_info *stu,int n)
+{
+	int i,j;
+	struct stu_info tmp;
+	for(i=0;i<n;i++)
+	{
+		for(j=0;j<n-i-1;j++)
+		{
+			if(((stu+j)->cls>(stu+j+1)->cls)||((stu+j)->cls==(stu+j+1)->cls)&&((stu+j)->num>(stu+j+1)->num))
+			{
+				tmp = *(stu+j);
+				*(stu+j) = *(stu+j+1);
+				*(stu+j+1) = tmp;
+			} 
+		}
+	}
+	return;
+}
+void input()
+{
+	int i;
+	char y[5];
+	for(i=0;;i++)
+	{
+		printf("Id ");scanf("%s",stu[i].num);
+		printf("class ");scanf("%d",&stu[i].cls);
+		printf("name ");scanf("%s",stu[i].name);
+		printf("score1 ");scanf("%f",&stu[i].maths);
+		printf("score2 ");scanf("%f",&stu[i].physics);
+		printf("score3 ");scanf("%f",&stu[i].english);
+		printf("Continue?\n");
+		again1:
+		scanf("%s",y);
+		if(strcmp(y,"yes")==0) continue;
+		else if(strcmp(y,"no")==0)
+		{
+			N=i+1;
+			menu();
+			break;
+		}
+		else
+		{
+			printf("wrong input\n");
+			goto again1;
+		}
+	}
+}
+void del(struct stu_info* stu)
+{
+	char key[10];char y[5];
+	scanf("%s",key);
+	int i;
+	for (i=0;i<N;i++)
+	{
+		if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->name,key)==0)
+		{
+			N--;
+			for(int j=i;j<N;j++)
+			{
+				*(stu+j)=*(stu+j+1);
+			}
+		}
+	}
+	output();
+	printf("Continue?\n");
+	again2:
+		scanf("%s",y);
+		if(strcmp(y,"yes")==0) del(stu);
+		else if(strcmp(y,"no")==0)
+		{
+			N=i;
+			menu();
+		}
+		else
+		{
+			printf("wrong input\n");
+			goto again2;
+		}
+}
+void sel(struct stu_info* stu)
+{
+	char key[10];char y[5];int e=1,i;
+	scanf("%s",key);
+	for (i=0;i<N;i++)
+	{
+		if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->name,key)==0)
+		{
+			e=0;
+			printf("%s %d %s %.1f %.1f %.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].maths,stu[i].physics,stu[i].english);
+		}
+	}
+	if(e) printf("there is no eligible student\n");
+	printf("Continue?\n");
+	again3:
+		scanf("%s",y);
+		if(strcmp(y,"yes")==0) sel(stu);
+		else if(strcmp(y,"no")==0)
+		{
+			menu();
+		}
+		else
+		{
+			printf("wrong input\n");
+			goto again3;
+		}
+}
+void order()
+{
+	sort(stu,N);
+	output();
+	menu();
+}
+void menu()
+{
+	int in;
+	printf("1.input\n");
+	printf("2.delete\n");
+	printf("3.select\n");
+	printf("4.order\n");
+	printf("5.output\n");
+	printf("6.quit\n");
+	printf("please input your option\n");
+	scanf("%d",&in);
+	switch(in)
+	{
+		case(1):
+			input();
+			break;
+		case(2):
+			del(stu);
+			break;
+		case(3):
+			sel(stu);
+			break;
+		case(4):
+			order();
+			break;
+		case(5):
+			output();
+			menu();
+			break;
+		case(6):
+			exit(0);
+		default:
+			printf("Wrong input\n");
+	}
+}
+int main()
+{
+	menu();
+	return 0;
+}