<prompt> Translate the following text to EnglishKwa sababu kama hiyo, kutumia ulimwengu huo kuwa kituo cha kusafiri kati ya nyota, isipokuwa kwa ajili ya biashara ya vitu fulani, si jambo la kiuchumi.  <response>: For a similar reason the use of the world as a base for interstellar travel, except for trade in certain items, is uneconomical. 