#include <bits/stdc++.h>
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define F(i, x, y) for (int i = (x); i <= (y); i++)
#define R(i, x, y) for (int i = (x); i >= (y); i--)
#define FIO(FILE) freopen(FILE".in", "r", stdin), freopen(FILE".out", "w", stdout)

using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
bool Mbe;

const int N = 2e5 + 5;

int n, rt, sum;
int vs[N], sz[N], mx[N], vis[N];

vector<int> G[N];

void ans(int u) {
	printf("! %d\n", u);
	fflush(stdout);
}

int qry(int u, int v) {
	printf("? %d %d\n", u, v);
	fflush(stdout);
	int d; scanf("%d", &d);
	return d;
}

void dfs(int u, int f) {
	sz[u] = 1, mx[u] = 0;
	for (int v : G[u]) {
		if (v == f || vs[v]) {
			continue;
		}
		dfs(v, u);
		mx[u] = max(mx[u], sz[v]);
		sz[u] += sz[v];
	}
	mx[u] = max(mx[u], sum - sz[u]);
	if (!rt || mx[u] < mx[rt]) {
		rt = u;
	}
}

void dfz(int u) {
	queue<int> q;
	q.push(u), sum = rt = 0;
	vector<int> nd;
	while (!q.empty()) {
		int u = q.front();
		q.pop(), sum++, nd.eb(u), vis[u] = 1;
		for (int v : G[u]) {
			if (vs[v] || vis[v]) {
				continue;
			}
			q.push(v);
		}
	}
	for (int u : nd) {
		vis[u] = 0;
	}
	if (sum == 1) {
		ans(u);
		return;
	}
	dfs(u, 0);
	vector<int> p;
	for (int v : G[rt]) {
		if (!vs[v]) {
			p.eb(v);
		}
	}
	sort(p.begin(), p.end(), [](int &x, int &y) {
		return sz[x] > sz[y];
	});
	assert((int)p.size() != 0);
	if (p.size() == 1) {
		if (qry(rt, p[0]) == 0) {
			ans(rt);
		} else {
			ans(p[0]);
		}
		return;
	} else if (p.size() == 2) {
		int d = qry(p[0], p[1]);
		if (d == 0) {
			vs[rt] = 1;
			dfz(p[0]);
		} else if (d == 1) {
			ans(rt);
			return;
		} else {
			vs[rt] = 1;
			dfz(p[1]);
		}
	} else {
		int d = qry(p[0], p[1]);
		if (d == 0) {
			vs[rt] = 1;
			dfz(p[0]);
		} else if (d == 1) {
			vs[p[0]] = vs[p[1]] = 1;
			dfz(rt);
		} else {
			vs[rt] = 1;
			dfz(p[1]);
		}
	}
}

void solve() {
	scanf("%d", &n);
	F (i, 1, n) {
		G[i].clear();
		vs[i] = 0;
	}
	F (i, 1, n) {
		int x, y;
		cin >> x >> y;
		if (x) {
			G[x].eb(i);
			G[i].eb(x);
		}
		if (y) {
			G[y].eb(i);
			G[i].eb(y);
		}
	}
	dfz(1);
}

bool Med;
int main() {
	// FIO("");
	// ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	cerr << (&Mbe - &Med) / 1048576.0 << " MB\n";
	int T = 1;
	scanf("%d", &T);
	while (T--) solve();
	cerr << (int)(1e3 * clock() / CLOCKS_PER_SEC) << " ms\n";
	return 0;
}