Give two examples of each of the following
(i) Animals having internal gills.
(ii) Animal groups showing tracheal respiration.
(iii) Anaerobes.
(i) Fishes and Pila, etc.
(ii) Insects, centipedes and millipedes, etc.
(iii) Certain bacteria, parasitic worms (e.g., Ascaris and tapeworm), etc.