单项选择题
以下程序运行后的输出结果是
#include<stdio.h>
main( )
FILE *fp;int i=20,j=30,k,n;
fp=fopen("d1.dat","w");
fprintf(fp,"%d\n",i);
fprintf(fp,"%d\n",j);
fclose(fp);
fp=fopen("d1.dat","r");
fscanf(fp,"%d%d",&k,&n);
printf("%d%d\n",k,n);
fclose(fp);
A.20 30
B.20 50
C.30 50
D.30 20