The real quesion is are you ready???
Answer:
co2 its the carbon dioxide oxcil
This is because elements are pure substances with only one atom. When two or more elements are combined, you get compound elements; which allows for more substances to be created.
Answer:
Circulatory system: Includes the arteries
Pumps blood
Includes the heart
Raspatory system : Provides oxygen to the blood
Preforms breathing
Includes the lungs
Explanation: