#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    vector<long long> a(n), b(n);
    long long maxto = 1e9;
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
    }
    bool flag = true;
    maxto = a[0];
    for (long long i = 0; i < n; i++) {
      cin >> b[i];
      if (i == n - 1) {
        continue;
      }
      if (i == 0) {
        long long e = min(a[i + 1], b[i]);
        a[i + 1] -= e;
        a[i] -= min(a[i], (b[i] - e));
        maxto = min(maxto, min(e, a[0]));
      } else {
        if (a[i] - b[i] > 0) {
          flag = false;
        }
        long long e = min(a[i], b[i]);
        a[i] -= e;
        long long t = min(b[i] - e, a[i + 1]);
        a[i + 1] -= t;
        if (t < b[i] - e) {
          a[0] -= min(maxto, b[i] - e - t);
          maxto -= min(maxto, b[i] - e - t);
        }
        maxto = min(maxto, t);
      }
    }
    if (!flag || b[n - 1] < a[0] + a[n - 1]) {
      cout << "NO\n";
    } else {
      cout << "YES\n";
    }
  }
  return 0;
}
