ExplanationA. True. Despite having higher daily energy needs, birds have plenty amount of digestive enzymes allowing shorter their intestines compared to the non-flying mammals.B. False. In birds, the characters of ventilation and lung structure make the gas exchange highly efficient. These are associated with the smaller the ratio of lung weight per body weight of birds compared to that in the non-flying mammals.C. True. Bats rapidly absorb and excrete water. This is related with optimizing body weight in flying locomotion.D. True. Bats have higher hematocrit level, leading to more oxygen concentration in the blood. This supplies more oxygen for flying activity.References1. Digestive Adaptations of Aerial Lifestyles. PHYSIOLOGY 30: 69 -78,2015.2. The structural and functional respiratory refinements in birds and bats. The Journal of Experimental Biology 203, 3045-3064 (2000).