1. is Biology
2. is C - bacteria
3. is A- carbohydrates
The ecosystem is an ecological system consisting of all of its biotic and abiotic factors
Scientists have concluded that the average human body contains approx. 37.2 trillion cells. However it depends upon your size compared an average human being. :)<span />
Answer:
The circulatory system circulates the blood to the whole body.
The respiratory system brings oxygen to the blood, and the circulatory system circulates the oxygenated blood to the cells.
Explanation:
