#include<bits/stdc++.h>
using namespace std; 

const int N = 100010; 
const int mod = 998244353; 

int add(int a, int b) {
	int c = a + b;
	if (c >= mod) c -= mod;
	return c; 
}
int dec(int a, int b) {
	int c = a - b;
	if (c < 0) c += mod;
	return c;  
}
int mul(int a, int b) {
	return 1ll * a * b % mod;
}
int qpow(int a, int b) {
	int p = 1;
	while (b) {
		if (b & 1)	
			p = mul(p, a); 
		a = mul(a, a);
		b >>= 1;  
	}
	return p; 
} 

int n, ans; 
vector<int> e[N];


int root, Mi, S; 
int mx[N], siz[N]; 
bool vis[N]; 


void findroot(int u, int fa) {
	siz[u] = 1; 
	mx[u] = 0; 
	for (int v : e[u]) {
		if (v == fa || vis[v]) 
			continue; 
		findroot(v, u); 
		siz[u] += siz[v]; 
		mx[u] = max(mx[u], siz[v]); 
	} 
	mx[u] = max(mx[u], S - siz[u]); 
	if (mx[u] < Mi) {
		Mi = mx[u]; 
		root = u; 
	}
}

/*
(du, fv)
fu = (\sum sizv)^2 - (\sum sizv^2) 
(sizu + (n - sizu))^2
gv = n^2 -  \sum sizv^2
fv = gu - 2sizv(n - sizv) 
du^2fu * (\sum fv)
2dufu * (\sum fv*dv)
fu * (dv^2fv) 
(du + dv) ^ 2 * fu * fv
*/

int g[N]; 
void dfs2(int u, int f) {
	siz[u] = 1; 
	g[u] = mul(n, n); 
	for (int v : e[u])
		if (v != f) {
			dfs2(v, u); 
			siz[u] += siz[v]; 
			g[u] = dec(g[u], qpow(siz[v], 2)); 
		}
	g[u] = dec(g[u], qpow(n - siz[u], 2)); 
}

int Dep[N], Siz[N], f[N];
int S1, S2, S3, s1, s2, s3;  
void dfs(int u, int fa) {
	Dep[u] = Dep[fa] + 1;
	Siz[u] = 1;  
	f[u] = 0; 
//	cerr << "?dfs:" << u << endl;
//	cerr << "?Dep:" << Dep[u] << endl;
	for (int v : e[u]) {
		if (v == fa || vis[v]) 
			continue; 
		dfs(v, u);
		Siz[u] += Siz[v];
	}
	f[u] = dec(g[u], mul(mul(2, Siz[u]), n - Siz[u])); 
//	cerr << "?u, f, g:" << u << ' ' << f[u] << ' ' << g[u] << endl;
	ans = add(ans, mul(mul(qpow(Dep[u], 2), f[u]), S1)); 
	ans = add(ans, mul(mul(2, mul(f[u], Dep[u])), S2)); 
	ans = add(ans, mul(f[u], S3)); 
	s1 = add(s1, f[u]);
	s2 = add(s2, mul(f[u], Dep[u])); 
	s3 = add(s3, mul(qpow(Dep[u], 2), f[u])); 
}
void divide(int u) {
//	cerr << "divide:" << u << endl;
	S1 = S2 = S3 = 0; 
	Dep[u] = 0; 
	vis[u] = 1; 
	Siz[u] = 1; 
	for (int v : e[u]) {
		if (vis[v]) 
			continue;
		
		s1 = s2 = s3 = 0;
		 
		dfs(v, u);
		Siz[u] += Siz[v];  
		
		int fu = dec(g[u], mul(mul(2, Siz[v]), n - Siz[v]));
		ans = add(ans, mul(fu, s3));  
		
		S1 = add(S1, s1); 
		S2 = add(S2, s2);
		S3 = add(S3, s3); 
	}
//	cerr << "?" << ans << endl;
	for (int v : e[u]) {
		if (vis[v])
			continue; 
			
		root = 0, Mi = 0x7fffffff, S = Siz[u]; 
		findroot(v, u);
		divide(root); 
	}
	
}

void init() {
	ans = 0;
	for (int i = 1; i <= n; i ++) {
		e[i].clear(); 
		vis[i] = 0; 
	}
}
void solve() {
	cin >> n;
	init(); 	
	for (int i = 1; i < n; i ++) {
		int u, v; 
		cin >> u >> v; 
		e[u].emplace_back(v); 
		e[v].emplace_back(u); 
	}
	
	dfs2(1, 0); 
	
	root = 0, Mi = 0x7fffffff, S = n; 
	findroot(1, 0); 
	divide(1); 
	cout << mul(ans, qpow(qpow(1ll * n * (n - 1) / 2 % mod, mod - 2), 2)) << endl; 
}


int main() {
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0); 
	int T;
	cin >> T;
	while (T --)
		solve(); 
	return 0; 
}