code: def _replace_words(replacements, string):
      
      output_lines = []
      for line in string.split('\n'):
          output_words = []
          for word in line.split(' '):
              new_word = replacements.get(word, word)
              output_words.append(new_word)
          output_lines.append(output_words)
      return '\n'.join(' '.join(output_words) for output_words in output_lines)
docs: Replace words with corresponding values in replacements dict.
  
      Words must be separated by spaces or newlines.