My postcard is still on the desk. Why ______ you ______ it

A. haven't ; posted
B. didn't ; post
C. wasn't ; posting
D. won't ; post

请补充main 函数，该函数的功能是：把文本文件B中的内容追加到文本文件A的内容之后。
例如，文佃的内容为“I’m ten.”，文件A的内容为“I’ m a student!”，追加之后文件A的内容为“I’m a student !I’m ten.”
注意：部分源程序给出如下。
请勿改动主函数main 和其他函数中的任何内容，仅在函数main 的横线上填入所编写的若干表达式或语句。
试题程序：
# include＜stdio, h＞
#include＜conio. h＞
#define N 80
main()

FILE *fp, * fp1, *fp2;
int i;
char c[N] ,t, ch;
clrscr ();
if ((fp=fopen ("A. dat ", "r") ) == NULL)

printf ("file A cannot be opened\n");
exit (0);

printf("\n A contents are : \n\n");
for (i=0; (ch=fgetc (fp)) !=EOF; i++)

C [i]=ch;
putchar (c [i]);
fclose (fp);
if((fp=fopen ("B. dat", "r") )==NULL)

printf ("file B cannot be opened\n");
exit (0);

printf("\n\n\nB contents are : \n\n");
for (i=0; (ch=fgetc (fp)) !=EOF; i++)

c [i] =ch;
putchar (c [i]);

fclose (fp);
if ( (fp1=fopen ("A.dat" ,"a")) 【1】 (fp2
=fopen ("B. dat", "r") ) )

while ( (ch=fgetc (fp2)) !=EOF)
【2】 ;

else

printf("Can not open A B !\n");

fclose (fp2);
fclose (fp1);
printf ("\n***new A contents***\n\n");
if ( ( fp=fopen ("A. dar", "r") )==NULL)

printf ("file A cannot be opened\n");
exit (0);

for (i=0; (ch=fgetc (fp)) !=EOF;i++)

c [i] =ch;
putchar (c [i] );

【3】 ;