#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
using namespace std;
const long long nmax = 1000005;
long long t, n, a[nmax], b[nmax], tz_a[nmax], tz_b[nmax];
long long check(long long init) {
  for (long long i = 1; i <= n; i++) {
    tz_a[i] = a[i];
  }
  for (long long i = 1; i <= n; i++) {
    tz_b[i] = b[i];
  }
  tz_a[1] = max(0LL, tz_a[1] - (tz_b[1] - init));
  tz_a[2] = max(0LL, tz_a[2] - init);
  for (long long i = 2; i <= n; i++) {
    if (tz_b[i] < tz_a[i]) return 0;
    tz_b[i] -= tz_a[i];
    tz_a[i + 1] = max(0LL, tz_a[i + 1] - tz_b[i]);
  }
  if (tz_a[1] > tz_b[n])
    return 1;
  else
    return 2;
}
string solve() {
  long long l = 0, r = b[1];
  while (l <= r) {
    long long mid = l + (r - l) / 2;
    long long t = check(mid);
    if (t == 2) {
      return "YES";
    } else if (t == 1) {
      r = mid - 1;
    } else if (t == 0) {
      l = mid + 1;
    }
  }
  return "NO";
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cerr.tie(0);
  cout.tie(0);
  srand(chrono::steady_clock::now().time_since_epoch().count());
  cin >> t;
  while (t--) {
    cin >> n;
    for (long long i = 1; i <= n; i++) cin >> a[i];
    for (long long i = 1; i <= n; i++) cin >> b[i];
    cout << solve() << '\n';
  }
}
