<prompt> Translate the following text to EnglishKama vipimo viwili au zaidi mfululizo si kuanguka ndani ya mipaka ya udhibiti, matokeo lazima kuelezwa na vipimo toxicant rejea lazima mara moja kurudia.  <response>: If two or more consecutive tests do not fall within the control limits, the results must be explained and the reference toxicant test must be immediately repeated. 