#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
long long pw(long long a, long long b) {
    long long r = 1;
    while (b) {
        if (b & 1) r = r * a % MOD;
        a = a * a % MOD;
        b >>= 1;
    }
    return r;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;
    cin >> T;
    while (T--) {
        string Cstr, Pstr;
        cin >> Cstr >> Pstr;
        bool pBig = false;
        if (Pstr.size() > 10) pBig = true;
        else if (Pstr.size() == 10 && Pstr >= "1000000007") pBig = true;
        if (pBig) {
            cout << 0 << "\n";
            continue;
        }
        long long P = 0;
        for (char ch : Pstr) P = P * 10 + (ch - '0');
        if (Cstr.size() <= 10) {
            long long C = 0;
            for (char ch : Cstr) C = C * 10 + (ch - '0');
            if (C < 2 * P - 1) {
                cout << 0 << "\n";
                continue;
            }
        }
        long long cmod = 0;
        for (char ch : Cstr) cmod = (cmod * 10 + (ch - '0')) % MOD;
        long long n = (cmod - P + 1) % MOD;
        if (n < 0) n += MOD;
        if (n < P) {
            cout << 0 << "\n";
            continue;
        }
        long long ans = 1;
        if (P <= MOD - 1 - P) {
            for (long long i = 0; i < P; i++) {
                ans = ans * (n - i) % MOD;
            }
        } else {
            long long comp = 1;
            for (long long i = 1; i <= n - P; i++) {
                comp = comp * i % MOD;
            }
            for (long long i = n + 1; i < MOD; i++) {
                comp = comp * i % MOD;
            }
            ans = (MOD - 1) * pw(comp, MOD - 2) % MOD;
        }
        cout << ans << "\n";
    }
    return 0;
}