Answer:
Oxygen
Explanation:
The heart, like any organ, requires blood for oxygen and other nutrients so it can do its work. The heart does not gather oxygen or nutrients from the blood flowing inside it. Instead, it receives blood from coronary arteries that eventually carry blood into the heart muscle.
Buffers maintain a pretty stable pH level, resisting any large changes. When introduced to a base, it will act as an acid to counteract it, and vice versa.
To build a complete picture of the animals and plants that were living at a particular time in the past. ... In addition, the rock itself provides much useful information about the environment in which it and the fossils were formed.
C.there is no relationship between metabolic rate and body temperature.
