A
it's the most grammatically correct and understandable
If the inner lining of the air sacs neither thin nor highly vascularized, then it can be inferred that AIR SACS ARE CANNOT BE THE SITES OF GASEOUS EXCHANGE BETWEEN AIR AND BLOOD. Air sacs are generally lined with mucus and surrounded with blood capillaries.
In case of birds, air sacs play an important role in respiratory system.
The survival of the species is ensured by C. by protecting the fertilized eggs from predators. The protection provided by the male increases the hatch rate of the eggs, which means more young seahorses. The greater the number of hatchlings, the greater the likelihood that some will survive to adulthood and carry on the survival of the species.
Yes.You can change its inside or outside
