#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
const i64 P = 998244353;
i64 qpow(i64 x, i64 y, i64 p = P) {
    i64 res = 1 % p;
    x %= P;
    while (y) {
        if (y & 1) res = res * x % p;
        x = x * x % p;
        y >>= 1;
    }
    return res;
}
void solve() {
    int n;
    cin >> n;
    vector<i64> sz(n + 1), sum(n + 1);
    vector<vector<i64>> G(n + 1);
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    i64 ans = 0;
    auto dfs = [&](auto self, int u, int fa) -> void {
        sz[u] = 1;
        for (auto v : G[u]) {
            if (v == fa) continue;
            self(self, v, u);
            sz[u] += sz[v];
            ans = (ans + (n - sz[v]) * (n - sz[v]) % P * sz[v] * sz[v] % P) % P;
            ans = (ans + 2 * sum[u] * sum[v] % P) % P;
            sum[u] = (sum[u] + sum[v]) % P;
        }
        ans = (ans + 2 * (n - sz[u]) * (n - sz[u]) % P * sum[u] % P) % P;
        sum[u] = (sum[u] + sz[u] * sz[u] % P) % P;
    };
    dfs(dfs, 1, 0);
    i64 m = (n * (n - 1) / 2) % P;
    ans = ans * qpow(m * m % P, P - 2) % P;
    cout << ans << '\n';
}
int main() {
    ios::sync_with_stdio(0); cin.tie(0), cout.tie(0);
    int t = 1; 
    cin >> t;
    while(t--) solve();
    return 0;
}