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

using ULL = unsigned long long;
const ULL base = 19260817;

void solve() {
  int n, m;
  cin >> n >> m;
  vector<string> s(n), t(n);
  for (int i = 0; i < n; i++) {
    cin >> s[i];
    t[i] = s[i] + s[i];
  }
  vector<vector<ULL>> h(n, vector<ULL>(m * 2));
  for (int i = 0; i < n; i++) {
    auto &cur = t[i];
    h[i][0] = cur[0] - 'a' + 1;
    for (int j = 0; j + 1 < m * 2; j++) {
      h[i][j + 1] = h[i][j] * base + cur[j + 1] - 'a' + 1;
    }
  }
  vector<ULL> p(m * 2 + 1);
  p[0] = 1;
  for (int i = 1; i < m * 2 + 1; i++) {
    p[i] = p[i - 1] * base;
  }
  auto calc = [&](int id, int l, int r) {
    auto &cur = t[id];
    ULL res = h[id][r];
    if (l) res -= h[id][l - 1] * p[r - l + 1];
    return res;
  };
  auto qry = [&](int i, int j) {
    ULL tar = calc(j, 0, m - 1);
    for (int k = 0; k < m; k++) {
      if (calc(i, k, k + m - 1) == tar) return 1;
    }
    return 0;
  };
  if (n <= 1000) {
    vector<vector<int>> ans(n, vector<int>(n));
    for (int i = 0; i < n; i++) {
      for (int j = i; j < n; j++) {
        ans[i][j] = ans[j][i] = qry(i, j);
      }
    }
    int q;
    cin >> q;
    while (q--) {
      int x, y;
      cin >> x >> y;
      x--, y--;
      cout << (ans[x][y] ? "Yes\n" : "No\n");
    }
  } else {
    int q;
    cin >> q;
    while (q--) {
      int x, y;
      cin >> x >> y;
      x--, y--;
      cout << (qry(x, y) ? "Yes\n" : "No\n");
    }
  }
}
int main() {
  cin.tie(0)->sync_with_stdio(0);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}