input: Write a function to respond to user queries.
  assert respond_to_query('What is the price?') == 'The price of our product is $30.'
  assert respond_to_query('Where can I buy it?') == 'You can buy it from our online store or from select retailers.'
  assert respond_to_query('How do I use it?') == 'Follow the instructions in the user manual.'
  assert respond_to_query('What is the warranty period?') in ['I am sorry, I do not understand your question.',
                                                              'Can you be more specific?',
                                                              'Please ask a specific question about the product.']
output: def respond_to_query(query):
      responses = {
          'What is the price?': 'The price of our product is $30.',
          'Where can I buy it?': 'You can buy it from our online store or from select retailers.',
          'How do I use it?': 'Follow the instructions in the user manual.'
      }
      default_responses = [
          'I am sorry, I do not understand your question.',
          'Can you be more specific?',
          'Please ask a specific question about the product.'
      ]
      return responses.get(query, default_responses[0])