Which of the following has the most primitive respiratory system? by Sunday | Jun 29 | Biology WAEC | 0 comments A. Rat B. Fish C. Toad D. Grasshopper E. Lizard Correct Answer: Option D – Grasshopper Users Also Read These:Write the respiratory structure of amoeba, five day…List FOUR characteristics of respiratory surfaces. -…In birds, loss of appetite, respiratory difficulties…The most efficient respiratory structure used by…A pulley system has three pulleys in the fixed block…