//
  // Created by ronal on 2/11/2023.
  // Problem Description Link.
  // https://practice.geeksforgeeks.org/problems/valid-string/0
  
  #include <bits/stdc++.h>
  using namespace std;
  
  string isValid(string s){
      stack<char> stak;
      char c;
  
      for(int i = 0; i < s.size(); i++){
          if(s[i] == '0'){
              stak.push(s[i]);
              continue;
          }else if(stak.empty()){
              return "no
  ";
          }else if(s[i] == '1'){
              stak.pop();
          }
      }
  
      if(stak.empty()){
          return "yes
  ";
      }else{
          return "no
  ";
      }
  
  }
  
  int main() {
      int tests, size;
      string s;
  
      cin >> tests;
      for(int i = 0; i < tests; i++){
          cin >> size;
          cin.ignore();
          getline(cin, s);
          cout << isValid(s);
      }
      return 0;
  }