#include <bits/stdc++.h>
#define rep(i, j, k) for (int i = (j); i <= (k); i++)
#define per(i, j, k) for (int i = (k); i >= (j); i--)
#define pb push_back
#define eb emplace_back
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
using VI = std::vector<int>;
using ll = long long;
using PII = std::pair<int, int>;
using db = double;
using namespace std;

using hashv = pair<int, int>;
constexpr int MOD1 = 1000000007, MOD2 = 1000000009;
hashv operator + (hashv a, hashv b) {
	int c1 = a.fi + b.fi, c2 = a.se + b.se;
	if (c1 >= MOD1) c1 -= MOD1;
	if (c2 >= MOD2) c2 -= MOD2;
	return {c1, c2};
}

hashv operator - (hashv a, hashv b) {
	int c1 = a.fi - b.fi, c2 = a.se - b.se;
	if (c1 < 0) c1 += MOD1;
	if (c2 < 0) c2 += MOD2;
	return {c1, c2};
}

hashv operator * (hashv a, hashv b) { 
	return {1ll * a.fi * b.fi % MOD1, 1ll * a.se * b.se % MOD2}; 
}

const int N = 101000;
hashv ps[N], vals[N];
int n, m;

void solve() {
	cin >> n >> m;
	hashv base(13331, 23333);
	rep(i, 1, n) {
		string s;
		cin >> s;
		s = "?" + s;
		ps[m] = make_pair(s[m], s[m]);
		hashv coef = base;
		per(j, 1, m - 1) {
			ps[j] = coef * hashv(s[j], s[j]) + ps[j + 1];
			coef = coef * base;
		}
		hashv q = hashv(0, 0);
		vals[i] = ps[1];
		coef = base;
		rep(j, 2, m) {
			q = q * base + hashv(s[j - 1], s[j - 1]);
			vals[i] = min(vals[i], ps[j] * coef + q); 
			coef = coef * base;
		}
	}
	int q;
	cin >> q;
	rep(i, 1, q) {
		int x, y;
		cin >> x >> y;
		cout << (vals[x] == vals[y] ? "Yes" : "No") << "\n";
	}
}

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);

	int t;
	cin >> t;
	while (t--) {
		solve();
	}
}