#include <bits/stdc++.h>
using namespace std;
using LL = long long;
const int mod = 998244353;
#define int long long
LL norm(LL x) {
    if (x >= mod)x -= mod;
    if (x < 0)x += mod;
    return x;
}

LL add(LL x, LL y) { return norm(x + y); }
LL sub(LL x, LL y) { return norm(x - y + mod); }
LL mul(LL x, LL y) { return x % mod * y % mod; }

LL ksm(LL a, LL b) {
    LL res = 1;
    while (b) {
        if (b & 1)res = res * a % mod;
        b >>= 1;
        a = a * a % mod;
    }
    return res;
}

void solve() {
    int n;cin >> n;
    vector<vector<int>>e(n + 1);
    for (int i = 1;i < n;i++) {
        int a, b;cin >> a >> b;
        e[a].push_back(b);
        e[b].push_back(a);
    }
    vector<LL>siz(n + 1), sum(n + 1);

    LL E = 0;
    auto dfs = [&](auto&& ff, int u, int fa)->void {
        siz[u] = 1;
        sum[u] = 0;
        for (int v : e[u]) {
            if (v == fa)continue;
            ff(ff, v, u);
            siz[u] += siz[v];
            // cout << u << "->" << v << "\n";
            // cout << siz[v] << " " << n - siz[v] << "\n";
            E = add(E, mul(mul(siz[v], siz[v]), mul(n - siz[v], n - siz[v])));
            // cout << E << "\n";
            sum[u] = add(sum[u], sum[v]);
        }
        sum[u] = add(sum[u], mul(siz[u], siz[u]));
        LL res = 0;
        for (int v : e[u]) {
            if (v == fa)continue;
            LL x = n - siz[v];
            LL tmp = sub(sum[v], mul(siz[v], siz[v]));
            tmp = mul(tmp, mul(x, x));
            tmp = mul(2, tmp);
            E = add(E, tmp);
            
            tmp = mul(res, sum[v]);
            tmp = mul(2, tmp);
            E = add(E, tmp);
            res = add(res, sum[v]);
        }
    };
    dfs(dfs, 1, 0);

    LL inv = ksm(1LL * n * (n - 1) / 2, mod - 2);
    inv = mul(inv, inv);
    LL ans = mul(E, inv);

    cout << ans << "\n";
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int T = 1;
#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif
    cin >> T;
    while (T--)
        solve();
    return 0;
}