下列程序将文件f1的内容先在屏幕上显示,然后复制到文件f2, 下划线【1】应该为()main(){ FILE*fp1,*fp2;if((fp1=fopen(“f1”,”r”))==NULL){printf(“cannotopenf1\n”);exit(0);}if((fp2=fopen(“f2”,”w”))==NULL){printf(“cannotopenf2\n”);exit(0);}while(!feof(fp1)) putchar(fgetc(fp1));【1】_;while(!feof(fp1))【2】;fclose(fp1);fclose(fp2);}