diff --git a/作业2.7.c b/作业2.7.c
new file mode 100644
index 0000000..bcb5f85
--- /dev/null
+++ b/作业2.7.c
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h> 
+typedef struct Student{
+	char id[100];
+	int cl;
+	char name[100];
+	float score1;
+    float score2;
+    float score3;
+    float total_score;
+}Student;
+void getinput(int *type,int *p1,int *p2,int *p3){
+	scanf("%d",type);
+	if(*type==1||*type==2){
+		scanf("%d-%d",p1,p2);
+	}else if(*type==3){
+		char temp[20];
+		scanf("%s",temp);
+		*p1=temp[0];
+	}else if(*type==5){
+		scanf("%d.%d-%d",p1,p2,p3);
+	}else{
+		scanf("%d",p1);
+	}
+}
+void query(Student *students,int numStudents,int type,int p1,int p2,int p3,Student *results,int *numResults){
+    int i;
+    *numResults = 0;
+    char temp1[20], temp2[20],temp3[20];
+    sprintf(temp1, "%d", p1);
+    sprintf(temp2, "%d", p2);//¸ñʽ»¯Êý¾ÝдÈëÁÙʱ×Ö·û´® 
+    sprintf(temp3,"%d",p3);
+    for(i=0; i<numStudents; i++){
+    	students[i].total_score = students[i].score1 + students[i].score2 + students[i].score3;
+        switch(type){
+        	
+            case 1:
+                if(students[i].cl>=p1&&students[i].cl<=p2){
+                    results[(*numResults)++] = students[i];//°à¼¶ºÅÔÚp1-p2ÄÚ 
+                }
+                break;
+            case 2:
+                if(strcmp(students[i].id,temp1)>=0 && strcmp(students[i].id,temp2)<=0){
+                    results[(*numResults)++] = students[i];//ѧºÅÔÚp1-p2ÄÚ 
+                }
+                break;
+            case 3:
+                if(students[i].name[0]==p1){
+                    results[(*numResults)++] = students[i];//Ãû×ÖÒÔÌض¨×Öĸ¿ªÍ·µÄѧÉú
+                }
+                break;
+            case 4:
+                if(students[i].total_score>=p1){
+                    results[(*numResults)++] = students[i];//×Ü·Ö´óÓÚµÈÓÚÌض¨·ÖÊýµÄѧÉú
+                }
+                break;
+            case 5:
+                if(students[i].cl==p1 && strcmp(students[i].id,temp2)>=0 && strcmp(students[i].id,temp3)<= 0){
+                    results[(*numResults)++] = students[i];//Ìض¨°à¼¶¡¢Ìض¨Ñ§ºÅ·¶Î§µÄѧÉú
+                }
+                break;
+        }
+    }
+}
+void sort(Student student[],int n){
+	int i,j;
+	for(i=0;i<n-1;i++){
+		for(j=0;j<n-1-i;j++){
+			if(student[j].cl>student[j + 1].cl||(student[j].cl==student[j + 1].cl&&student[j].total_score<student[j + 1].total_score)){
+				Student temp=student[j];
+				student[j]=student[j+1];
+				student[j+1]=temp;
+			}
+		}
+	}
+}
+void printResults(Student *results, int numResults){
+    int i;
+    for(i=0; i<numResults; i++){
+        printf("%s %d %s %.1f %.1f %.1f\n", results[i].id, results[i].cl, results[i].name, results[i].score1, results[i].score2, results[i].score3);
+    }
+}
+int main(){
+	Student students[7] = {
+// ¶¨ÒåÈ«¾ÖѧÉúÊý×é
+        {"10001", 11, "Zhang", 99.5, 88.5, 89.5},
+        {"10002", 12, "Yang", 77.9, 56.5, 87.5},
+        {"10003", 11, "Liang", 92.5, 99.0, 60.5},
+        {"10004", 11, "Cai", 89.6, 56.9, 90.5},
+        {"10005", 14, "Fu", 55.6, 67.9, 98.9},
+        {"10006", 12, "Mao", 22.1, 45.9, 99.2},
+        {"10007", 13, "Zhan", 35.6, 67.9, 88.0}
+    };
+	int type;
+    int p1,p2,p3;
+    printf("ÇëÊäÈë²éѯÀàÐͺÍÖµ£¨¸ñʽ£ºÀàÐÍ Öµ£©£º");
+    getinput(&type,&p1,&p2,&p3);
+    Student results[7];
+    int numResults;
+    query(students,7,type,p1,p2,p3,results,&numResults);
+    sort(results,numResults);
+    printResults(results,numResults);
+	
+	return 0;
+}