#include <bits/stdc++.h>
using namespace std;
const long double PI = 3.141592653589793238462643383279502884;
const long long PRIME1 = 1e9 + 7;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
long long minll(long long a, long long b) { return a <= b ? a : b; }
long long maxll(long long a, long long b) { return a >= b ? a : b; }
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int a[1000010], b[1000010];
    for (int i = 0; i < n; i++) cin >> a[i];
    for (int i = 0; i < n; i++) cin >> b[i];
    long long need = 0, add = 0, xtra = 2e9;
    int f = 1;
    for (int i = n - 1; i > -1 && f; i--) {
      if (b[i] < need) {
        cout << "NO"
             << "\n";
        f = 0;
        break;
      }
      long long t = (long long)b[i] - (long long)a[i];
      long long addi = minll(xtra, maxll(0LL, t - need));
      add += addi;
      xtra = minll(xtra - addi, (long long)b[i] - need - addi);
      need = maxll(0LL, need - t);
    }
    if (f) {
      if (add >= need) {
        cout << "YES"
             << "\n";
      } else {
        cout << "NO"
             << "\n";
      }
    }
  }
  return 0;
}
