Answer:
1. to carry oxygen from the lungs to the body tissues
2. seven (7) or (4)
3.Humans can't live without blood body's organs couldn't get the oxygen and nutrients they need to survive,
Explanation:
The study of the relationship between structures and functions is at the very heart of biology. This relationship is expressed in living beings by the adaptation of the first to the second and poses a series of absolutely fundamental problems, such as the relationship between causality and finality, analogy and homology, structural improvement and evolutionary level, etc.
For example, the structure of the hand is related to its function, thanks to the fingers and the thumb it is easy to wear and store objects.
The zigzag structure of the intestine is related to its absorption function, as this makes it possible to increase the contact surface between the alimentary bolus and the intestinal wall, and thus to increase the absorption.
Acceleration is defined as the rate of change in the speed of a moving body or vehicle typically.
<u>Explanation:</u>
In the branch of mechanics, the aspect of acceleration is considered to be a property of the vector. And acceleration always occurs in a specific positive direction.
The formula for determining acceleration is change in the rate of velocity over a specific time, and is therefore measured as the ratio of delta velocity by delta time unit.

The unit of acceleration is distance per time unit squared or m / second squared.
Physical activity causes an increase in your heart rate. Your body have to change the way it behaves so you don’t get ill or sick or pass out during physical exertion