Mouth, esophagus, stomach, small intestines, large intestines, out the body
They are named for the places where geologists first described rocks or fossils from that time.
They replace the lost ions by active uptake through active transport
of ions from the surrounding waters. This is exhibited in freshwater fishes that
actively take in these ions through the gills. Most of the ions involved in osmoregulation in freshwater are those of Na+ and Cl-.
The best answer would be d but im not entirely sure
