text: #include <stdio.h>
  #include <string.h>
  
  struct Books {
      char title[50];
      char author[50];
      char subject[100];
      int book_id;
  };
  
  int main() {
      struct Books Book1; /* 声明 Book1,类型为 Books */
      struct Books Book2; /* 声明 Book2,类型为 BooKs */
  
      /* Book1详述 */
      strcpy(Book1.title, "C Programming");
      strcpy(Book1.author, "Nuba Ali");
      strcpy(Book1.subject, "C Programming Tutorial");
      Book1.book_id = 6495407;
  
      /* Book2 详述 */
      strcpy(Book2.title, "Telecom Billing");
      strcpy(Book2.author, "Zara Ali");
      strcpy(Book2.subject, "Telecom Billing Tutorial");
      Book2.book_id = 6495700;
  
      /* 输出Book1 信息 */
      printf("Book1 title : %s\n", Book1.title);
      printf("Book1 author : %s\n", Book1.author);
      printf("Book1 subject : %s\n", Book1.subject);
      printf("Book1 book_id: %d\n", Book1.book_id);
  
      /* 输出Book2 信息 */
      printf("Book2 title: %s\n", Book2.title);
      printf("Book2 author: %s\n", Book2.author);
      printf("Book2 subject: %s\n", Book2.subject);
      printf("Book2 book_id: %d\n", Book2.book_id);
  
      return 0;
  }