Complex sentence: The Doctor arrives, struggling to hold off his body's attempt to regenerate to rid itself of the spectrox, and is given a limited air supply and equipment from Jek to find and milk the queen bat.
Split into simpler sentences: The Doctor arrives, struggling to hold off his body's attempt to regenerate to rid itself of the spectrox. Jek provides him with a limited air supply and equipment and directions to find and milk the queen bat.