#include <bits/stdc++.h>
using namespace std;
int check(vector<int>& A, vector<int>& B, int ans) {
  vector<int> AP = A;
  vector<int> BP = B;
  AP.push_back(A[0] - ans);
  AP[0] = ans;
  int carry = 0;
  for (int i = 0; i < BP.size(); i++) {
    if (BP[i] < AP[i]) return 1;
    BP[i] -= AP[i];
    AP[i] = 0;
    AP[i + 1] -= min(AP[i + 1], BP[i]);
  }
  if (*AP.rbegin() == 0) return 0;
  return -1;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int T;
  cin >> T;
  while (T--) {
    int n;
    cin >> n;
    vector<int> A(n);
    vector<int> B(n);
    for (auto& Ai : A) cin >> Ai;
    for (auto& Bi : B) cin >> Bi;
    int high = A[0];
    int low = 0;
    while (low < high) {
      int mid = (low + high) / 2;
      int res = check(A, B, mid);
      if (res == 0) {
        low = high = mid;
        break;
      }
      if (res < 0) {
        low = mid + 1;
      }
      if (res > 0) {
        high = mid - 1;
      }
    }
    if (check(A, B, low) == 0) {
      cout << "YES\n";
    } else {
      cout << "NO\n";
    }
  }
}
