<prompt> Translate the following text to English11 Katika baadhi ya makundi, wauzaji wa barua husafirisha barua zao nyingi hadi maeneo ya chini ya mto ili kutumia faida ya viwango vya usafirishaji vya mikoa.  <response>: 10 11 In some classes, mailers transport much of their mail to downstream locations to take advantage of zoned rates for transportation. 