The answer is zona pellucida
Answer:
try Photoceptor to gisiual region
Answer: Due to formation of carbonic acid, increased CO2 level will decrease the pH of earth waters.
Carbon dioxide could form carbonic acid when dissolved into water. Since it was acid, it will lower the pH of the water. The level of carbon dioxide in human body is regulated because of the same reason. Higher or lower pH will have a harmful effect on the organism that live in the water.
The right answer would be b because as you learn more about it then it will become more clear