#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a, b;
int check(int val) {
  int pos;
  int r0;
  r0 = max(0, a[0] - val);
  int r = b[0] - val;
  int aux = max(0, a[1] - r);
  for (int i = 1; i < n - 1; i++) {
    if (aux > b[i]) return 1;
    r = b[i] - aux;
    aux = max(0, a[i + 1] - r);
  }
  if (aux > b[n - 1]) return 1;
  r = b[n - 1] - aux;
  if (r < r0) return -1;
  return 0;
}
void solve() {
  scanf("%d", &n);
  a.resize(n);
  b.resize(n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  for (int i = 0; i < n; i++) scanf("%d", &b[i]);
  int l = 0, r = b[0];
  while (l < r) {
    int mid = (l + r) / 2;
    if (check(mid) < 0) {
      l = mid + 1;
    } else
      r = mid;
  }
  if (check(l) == 0) {
    printf("YES\n");
  } else
    printf("NO\n");
}
int main() {
  int t;
  scanf("%d", &t);
  while (t--) {
    solve();
  }
  return 0;
}
