The Living World 8th Edition by George Johnson

تمرين 4

In order for amphibians to invade land, they had to develop which of the following?
A) a more efficient swim bladder
B) cutaneous respiration and lungs
C) watertight skin
D) shelled eggs
The evolution of the pulmonary veins was important for amphibians because it allowed
A) a single-loop circulation.
B) the metabolic rate to increase.
C) oxygenated blood to be pumped at higher pressures.
D) faster circulation to the lungs.