It may or may not turn acidic depending on the area or time of the year it is.
No, because “free” nitrogen is not combined with other kinds of atoms.
Most organisms can use nitrogen only once it has been "fixed" or combined with other elements to form nitrogen-containing compounds.
Answer:
Land vertebrates developed lungs, a new vein (the pulmonary vein) to take blood from them to the heart, and a double circulation, whereby the heart is effectively divided into two halves—one-half concerned with pumping incoming deoxygenated blood from the body to the lungs and the other with pumping oxygenated blood .
Explanation:
The edge of two crustal plates that shift are known as plates that transform.
A relatively small blood pressure gradient is generally insufficient to move blood through the veins under given conditions, thus venous return must be facilitated by valves within veins and two "pumps." ... As skeletal muscles contract, veins are squeezed to help propel the blood toward the heart.
