#include <bits/stdc++.h>
using namespace std;
namespace covnet {
int t;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    long long a[n];
    long long b[n];
    long long asum = 0;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      asum += a[i];
    }
    long long bsum = 0;
    for (int i = 0; i < n; i++) {
      cin >> b[i];
      bsum += b[i];
    }
    if (asum > bsum) {
      cout << "NO" << endl;
      continue;
    }
    long long need[n];
    for (int i = 0; i < n; i++) {
      need[i] = a[i] - b[i];
    }
    long long min[n];
    min[0] = 0;
    long long count = 0;
    for (int i = 0; i < n; i++) {
      count += need[i];
      if (count > min[0]) {
        min[0] = count;
      }
    }
    min[n - 1] = max(0LL, min[0] + need[n - 1]);
    for (int i = n - 2; i > 0; i--) {
      min[i] = max(0LL, min[i + 1] + need[i]);
    }
    bool works = true;
    for (int i = 0; i < n; i++) {
      if (min[i] > a[i]) {
        works = false;
      }
    }
    if (works) {
      cout << "YES" << endl;
    } else {
      cout << "NO" << endl;
    }
  }
  return 0;
}
}  // namespace covnet
int main() {
  covnet::main();
  return 0;
}
