Respiration in birds compared with respiration in humans

1.
The fish gill has filaments containing blood vessels, capillaries are in the lamellae. Usually the blood flows through the capillaries in the OPPOSITE direction as water flow. According to the diagram, if the blood flow is in THE SAME direction as the water flow the maximum oxygenation of the blood will be:
A) 100%
B) 50%
C) 20%
D) 10%
2.
A major difference between respiration in birds compared with respiration in humans:
A) air flows through the bird lung instead of inefficient tidal ventilation in the human lung
B) the bird lung does not have capillaries to carry oxygen to the body
c) the human lung is connected to anterior and posterior air sacs
D) the diffusion distance between air to the capillaries in the human lung is very far i.e. several centimeters
E) The humans breathe mainly through their skin