#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
static string norm(string s) {
    size_t i = 0;
    while (i + 1 < s.size() && s[i] == '0') ++i;
    return s.substr(i);
}
static int cmp(const string &a, const string &b) {
    string x = norm(a), y = norm(b);
    if (x.size() != y.size()) return x.size() < y.size() ? -1 : 1;
    if (x < y) return -1;
    if (x > y) return 1;
    return 0;
}
static string subBig(const string &a, const string &b) {
    string x = norm(a), y = norm(b);
    int n = x.size(), m = y.size();
    string r(n, '0');
    int borrow = 0;
    for (int i = 0; i < n; ++i) {
        int d = (x[n - 1 - i] - '0') - borrow;
        if (i < m) d -= (y[m - 1 - i] - '0');
        if (d < 0) { d += 10; borrow = 1; } else borrow = 0;
        r[n - 1 - i] = char('0' + d);
    }
    return norm(r);
}

static string addOne(const string &a) {
    string s = a;
    int c = 1;
    for (int i = (int)s.size() - 1; i >= 0 && c; --i) {
        c += s[i] - '0'; s[i] = char('0' + c % 10); c /= 10;
    }
    if (c) s.insert(s.begin(), '1');
    return s;
}
static int modInt(const string &s, int m) {
    long long r = 0;
    for (char c : s) r = (r * 10 + (c - '0')) % m;
    return (int)r;
}
static long long toIntIfSmall(const string &s, long long limit) {
    string t = norm(s);
    char buf[32]; snprintf(buf, sizeof(buf), "%lld", limit);
    if (t.size() > strlen(buf)) return -1;
    if (t.size() == strlen(buf) && t > string(buf)) return -1;
    return stoll(t);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    if (!(cin >> T)) return 0;
    while (T--) {
        string C, P;
        cin >> C >> P;
        C = norm(C); P = norm(P);

        if (P == "0") { cout << 1 << '\n'; continue; }

        long long pVal = toIntIfSmall(P, MOD);
        if (pVal < 0) { cout << 0 << '\n'; continue; }
        int k = (int)pVal;          
        if (cmp(C, P) < 0) { cout << 0 << '\n'; continue; }
        string n = addOne(subBig(C, P));   // n = C - P + 1
        if (cmp(n, P) < 0) { cout << 0 << '\n'; continue; }
        int n0 = modInt(n, MOD);
        if (n0 < k) { cout << 0 << '\n'; continue; }
        long long ans = 1;
        for (int i = 0; i < k; ++i) ans = ans * (n0 - i) % MOD;
        cout << ans << '\n';
    }
}