C++ :

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
const long long mod=(long long )(1e9+7);
int n,k;

long long power(long long a,long long p)
{
    long long res=1;
    while(p)
    {
        if(p&1)
            res=(a*res)%mod;
            a=(a*a)%mod;
            p>>=1;
    }
    return res;
}
long long solve(long long x)
{
    long long res;
    if(x==1) return 1;
    if(x==2) return 2;
    if(x==3) return 5;
    res=(power(2,x-1)%mod+((x-2)*power(2,x-3)%mod))%mod;
    return res;
}
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d%d",&n,&k);

        if(k>n)
        {
            printf("0\n");
            continue;
        }
        int x=n;
        x-=(k-1);
        printf("%lld\n",solve(x));
    }
    return 0;
}