#include <bits/stdc++.h>

#define boAshraf ios_base::sync_with_stdio(false); cin.tie(NULL);
#define ll long long
#define sz(s) (int)(s).size()
#define all(s) (s).begin(),(s).end()
using namespace std;

void File();

void sol();

const int N = 2e5 + 5;
int freq[N], a[N];

vector<pair<int, int>> best(3, {-1, -1});

struct Mo {
    int n, sq;

    Mo(int n) : n(n), sq(sqrt(n)) {}

    struct query {
        int l, r, id, block_id;

        query(int l, int r, int id, int sq) : l(l), r(r), id(id), block_id(l / sq) {}

        bool operator<(const query &other) const {
            if (block_id == other.block_id) return r < other.r;
            return block_id < other.block_id;
        }
    };

    vector<query> Q;

    void addQuery(int l, int r, int id) {
        Q.emplace_back(l, r, id, sq);
    }

    void add(int i) {
        if (!i) return;
        int x = a[i];
        int f = ++freq[x];
        bool found = 0;
        for (auto &[f2, x2]: best) {
            if (x2 == x) {
                found = 1;
                f2 = f;
            }
        }
        if (!found)best.emplace_back(f, x);

        sort(all(best), greater());
        if (sz(best) > 3)best.pop_back();
    }

    void remove(int i) {
        if (!i) return;
        int x = a[i];
        int f = --freq[x];
        bool found = 0;
        for (auto &[f2, x2]: best) {
            if (x2 == x) {
                found = 1;
                f2 = f;
            }
        }
        if (!found)best.emplace_back(f, x);

        sort(all(best), greater());
        if (sz(best) > 3)best.pop_back();
    }

    vector<pair<int, int>> process() {
        vector<pair<int, int>> ans(sz(Q),{-1,-1});
        sort(all(Q));
        int curL = 0, curR = -1; // 1-based
        for (auto [l, r, id, block_Id]: Q) {
            int need = (r - l + 1) / 3;
            while (curL > l) add(--curL);
            while (curR < r) add(++curR);
            while (curL < l) remove(curL++);
            while (curR > r) remove(curR--);

            sort(all(best), greater());

            int f1 = -1, x1 = -1;
            int f2 = -1, x2 = -1;
            tie(f1, x1) = best[0];
            tie(f2, x2) = best[1];
            if (f1 > need) ans[id].first = x1;
            if (f2 > need) ans[id].second = x2;
            assert(best[2].first <= need);
        }
        return ans;
    }
};

int main() {
    boAshraf
    File();
    int t = 1;
    cin >> t;
    while (t--) sol();
    return 0;
}

void sol() {
    int n, q;
    cin >> n >> q;

    vector<int> ord;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        ord.emplace_back(a[i]);
    }
    sort(all(ord));
    ord.erase(unique(all(ord)), ord.end());

    int D = sz(ord);
    for (int i = 1; i <= n; ++i) {
        a[i] = (int) (lower_bound(all(ord), a[i]) - ord.begin());
    }

    Mo mo(n);
    for (int i = 0; i < q; ++i) {
        int l, r;
        cin >> l >> r;
        mo.addQuery(l, r, i);
    }

    auto ans = mo.process();

    for (auto [id1, id2]: ans) {
        int ans1 = -1, ans2 = -1;
        if (id1 != -1) ans1 = ord[id1];
        if (id2 != -1) ans2 = ord[id2];
        if (ans1 > ans2) swap(ans1, ans2);

        if (ans1 == -1 && ans2 == -1) {
            cout << -1 << '\n';
        } else if (ans1 == -1) {
            assert(~ans2);
            cout << ans2 << '\n';
        } else {
            assert(ans1 != ans2);
            assert(~ans1);
            assert(~ans2);
            cout << ans1 << ' ' << ans2 << '\n';
        }
    }
    best = vector<pair<int, int>>(3, {-1, -1});
    for (int i = 0; i < D; ++i) freq[i] = 0;
}

void File() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}