diff --git a/作业2.7.c b/作业2.7.c
new file mode 100644
index 0000000..dc3ab91
--- /dev/null
+++ b/作业2.7.c
@@ -0,0 +1,78 @@
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+// ¶¨ÒåѧÉú½á¹¹Ìå
+struct Student {
+    int student_id;
+    int class_id;
+    char name[20];
+    double score1;
+    double score2;
+    double score3;
+};
+
+// ¶¨ÒåÈ«¾ÖѧÉúÊý×é
+struct Student student_data[] = {
+    {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}
+};
+
+// ¶¨ÒåѧÉúÊýÁ¿
+int student_count = sizeof(student_data) / sizeof(student_data[0]);
+
+// ±È½Ïº¯ÊýÓÃÓÚ°´°à¼¶´ÓСµ½´ó£¬Í¬°à¼¶°´×ܳɼ¨´Ó´óµ½Ð¡ÅÅÐò
+int compare_students(const void *a, const void *b) {
+    struct Student *student1 = (struct Student *)a;
+    struct Student *student2 = (struct Student *)b;
+
+    if (student1->class_id != student2->class_id) {
+        return student1->class_id - student2->class_id;
+    } else {
+        double total1 = student1->score1 + student1->score2 + student1->score3;
+        double total2 = student2->score1 + student2->score2 + student2->score3;
+        return (total2 - total1) > 0 ? 1 : -1;
+    }
+}
+
+// ²éѯѧÉúÐÅÏ¢º¯Êý
+void query_students(int query_type, char *query_value) {
+    for (int i = 0; i < student_count; i++) {
+        struct Student student = student_data[i];
+        double total = student.score1 + student.score2 + student.score3;
+
+        if (query_type == 1 && student.class_id >= query_value[0] && student.class_id <= query_value[2]) {
+            printf("%d %d %s %.1lf %.1lf %.1lf\n", student.student_id, student.class_id, student.name, student.score1, student.score2, student.score3);
+        } else if (query_type == 2 && student.student_id >= query_value[0] && student.student_id <= query_value[2]) {
+            printf("%d %d %s %.1lf %.1lf %.1lf\n", student.student_id, student.class_id, student.name, student.score1, student.score2, student.score3);
+        } else if (query_type == 3 && strncmp(student.name, query_value, strlen(query_value)) == 0) {
+            printf("%d %d %s %.1lf %.1lf %.1lf\n", student.student_id, student.class_id, student.name, student.score1, student.score2, student.score3);
+        } else if (query_type == 4 && total >= atof(query_value)) {
+            printf("%d %d %s %.1lf %.1lf %.1lf\n", student.student_id, student.class_id, student.name, student.score1, student.score2, student.score3);
+        } else if (query_type == 5 && student.class_id == query_value[0] && student.student_id >= query_value[2] && student.student_id <= query_value[4]) {
+            printf("%d %d %s %.1lf %.1lf %.1lf\n", student.student_id, student.class_id, student.name, student.score1, student.score2, student.score3);
+        }
+    }
+}
+
+int main() {
+    int query_type;
+    char query_value[20];
+
+    printf("ÇëÊäÈë²éѯÀàÐͺÍÖµ£¨¸ñʽ£ºÀàÐÍ Öµ£©£º");
+    scanf("%d %s", &query_type, query_value);
+
+    // ÅÅÐòѧÉúÐÅÏ¢
+    qsort(student_data, student_count, sizeof(struct Student), compare_students);
+
+    // ²éѯѧÉúÐÅÏ¢
+    query_students(query_type, query_value);
+
+    return 0;
+}
+