<prompt> Translate the following text to EnglishKwa mfano, hakuna ushahidi wa kutosha kuhusu athari za uzito kwa gharama katika darasa la kwanza na kiwango cha A, licha ya ushuhuda wa kina unaohusiana na hilo.  <response>: 2 Not enough is known about the effects of weight on costs in First Class and Standard A, despite extensive related testimony23. 