Answer:
itis responsible for the circulation as wel as purification of blood in the human body
Answer: FOSSIL
A rock-like copy of a plant,a feather,or a bone(natural things) is a FOSSIL
Explanation: Fossil can be defined as the preserved remains or trace or impression from a plant or animal that pre-existed in history or geological age,these remains are preserved in petrified form in the earth crust.
Fossils serves as the primary source of information about the history of life of a plant or animal on earth.
They are studied by archeologists.
The five types of fossils are; Carbon Fossils,Trace fossils, Body fossils, Molecular fossils and Pseudo fossils.
Answer:
the oxygen concentration decreases only when the air reaches the alveoli, which are the terminal branches of the respiratory system
Explanation:
The human respiratory system is responsible for taking in oxygen-rich air, and they expelling oxygen-poor air. The respiratory system consists of lungs, which helps in the exchange of gases: Oxygen and carbon dioxide.
The statement ''the oxygen concentration decreases only when the air reaches the alveoli, which are the terminal branches of the respiratory system'' explains the change in oxygen concentration of the inspired air