填空题 下面程序的运行结果后,文件t1.dat中的内容是____. #include<stdio.h> void WriteStr ( char *fn , char *str ) { FILE *fp ; fp = fopen( fn , "w" ) ; fputs( str , fp ) ; fclose( fp ) ; } int main( ) { WriteStr( "t1.dat" , "start" ) ; WriteStr( "t1.dat" , "end" ) ; return 0 ; }