A vaccination can produce immunity to smallpox
Answer:
#2 Heart rate monitor
Explanation:
To make sure she is keeping track of her heart rate
D.
This is because if you’re in high air polluted areas your lungs could be affected.
If you exercise in heat you’re more likely to have a heat stroke or pass out, which are both dangerous.
If equipment is made for something specific, using it wrong could result in physical injury.
I believe you answer is they both transmission signals through radio waves.
