Answer:
1. you feeling your heart beat increase and fastly
2. The physical changes are sweating and made you loses energy
3. when you are tired your heartbeat will be fast and your lungs will may not breath properly because of the activity
4. by the brain makes you think you run, eyes is to see for the activity, and lastly heart
5. by how your respiratory system and nervous system works through your body
Explanation:
pls correct me if I'm wrong and don't send me d3@th threats if I'm wrong