Answer:
Respiration is the process where oxygen is taken in and carbon dioxide is exhaled out and combustion means the burning of substances in the presence of oxygen
If their answer came out not the same as the accepted theory answer
<span>The answer is letter b. Human activities have polluted most of the fresh water supply that is fit for consumption. Letter b. explains the reason behind the water shortage which we are facing today, which is human activities have polluted most of the fresh water supply that is fit for consumption.</span>
Answer: medulla of the brain
The medulla of our brain is the control center of our heart rate. It either slows or speeds the heart beats per minute. If the medulla of the brain is not working correctly, our heart rate is also not being controlled correctly. We would not be able to live without the medulla. It helps in regulating blood pressure, breathing and transfer of neural messages from the brain to the spinal cord.