<prompt> Translate the following text to EnglishKwa kuongezea, chanzo cha mabaki ya uwekezaji ni mapato yaliyopatikana kutoka kwa mauzo yao ya bidhaa na huduma, ambayo fedha zilipata gharama za shughuli wakati mapato hayo yalipatikana.  <response>: Furthermore, the source of the invested balances is predominantly revenue earned from their sales of goods and services, for which the funds incurred costs of operations when that revenue was earned. 