<prompt> tafadhali geuza maudhui haya ya swahili kwenda kwa kiingereza.unaweza kufafanua kilichosababisha vipindi hivi, ikizingatiwa kuwa hakukuwa na moto wa mafuta au vyanzo vingine vya kutolewa kwa kaboni dioksidi kaboni wakati huo?  <response>: after re-reading that paragraph, can you think of why it would make a difference whether salt water or plain water is used for the mobile phase? 