<prompt> Translate the following text to EnglishKwa kuongezea, chanzo cha mabaki ya uwekezaji ni mapato yaliyopatikana kutoka kwa mauzo ya huduma, ambayo walipata gharama za shughuli wakati mapato yalipokelewa.  <response>: Furthermore, the source of the invested balances is predominantly revenue earned from the sales of services, for which they incurred costs of operations when the revenue was earned. 