执行以下程序后,test.txt文件的内容是(若文件能正常打开) ( )。#include <stdio.h>#include <stdlib.h>main( ){ FILE * fp; char * s1 = 'Fortran' , * s2 = 'Basic'; if((fp = fopen( 'test. txt' ,' wb' )) = = NULL) { prinff( 'Can't open test. txt file /n'); exit(1); } fwrite( s1 ,7,1 ,fp); /* 把从地址s1开始到7个字符写到fp所指文件中*/ fseek(fp,OL,SEEK_SET); /*文件位置指针移到文件开头*/ fwrite (s2,5,1,fp); felose (fp);}