code: def quantity_string(name, quantity_dict):
      '''Takes in an abbreviation for a quantity and a quantity dictionary,
         and returns a more descriptive string of the quantity as "name (units)."
         Raises ValueError if the name is not in quantity_dict
      '''
      if name not in quantity_dict.keys():
          raise ValueError('{0} is not present in quantity_dict'.format(name))
      return '{0} ({1})'.format(quantity_dict[name]['name'],
                                quantity_dict[name]['units']f quantity_string(name, quantity_dict):
      '''Takes in an abbreviation for a quantity and a quantity dictionary,
         and returns a more descriptive string of the quantity as "name (units)."
         Raises ValueError if the name is not in quantity_dict
      '''
      if name not in quantity_dict.keys():
          raise ValueError('{0} is not present in quantity_dict'.format(name))
      return '{0} ({1})'.format(quantity_dict[name]['name'],
                                quantity_dict[name]['units'])
docs: Takes in an abbreviation for a quantity and a quantity dictionary,
         and returns a more descriptive string of the quantity as "name (units)."
         Raises ValueError if the name is not in quantity_dict