#include<iostream>
using namespace std;
#define p 1000000007
_int64 Partition(_int64 n, _int64 k);
int main(){
    _int64 k, T,n;
    cin >> T;
    while (T--){
        cin >> n >> k;
        cout << Partition(n, k) << endl;
    }
    return 0;
}
_int64 Partition(_int64 n,_int64 k){
    _int64 i,x,result,l;
    x = (2 * n - k*(k-1))/(2 * k);
    if (x <= 0)
        return -1;
    l = n - (2 * x + k-1)*k / 2;
    l = k - l;
    result = 1;
    for (i = 1; i <= k; i++){
        result = result*x%p;
        if (i == l)
            x += 2;
        else
            x++;
    }
    return result;
}