关於TC所编一个小程序的问题·高手直接HI我

#include<stdlib.h>
#include<stdio.h>
#include<conio.h>
#include <time.h>
int dif_1();
int dif_2();
long t;
int ch;
void menu_1();
int menu_in();
int dif_1()
{
int dif_1;
dif_1 = rand()%10;
return dif_1;
}
int dif_2()
{
int dif_2;
dif_2 = rand()%100;
return dif_2;
}
void menu_1()
{
int i;
{
clrscr();
for(i=0;i<8;i++) printf("\n");
printf(" Difficuty Choose\n ");
printf("\n\n");
printf(" 1--Between 1 and 10\n\n");
printf(" 2--Between 1 and 100\n\n");
printf(" 3--Exit\n\n");
}
}
int menu_in()
{
int choose;
printf(" Choose:");
scanf("%