Answer:
If the heart rate monitor says you're working at 50 to 60% of your max heart rate, then the exercise is considered moderate. If the heart rate monitor shows that you're working at 70 to 85% of your heart rate then it's vigorous exercise. To find your maximum heart rate, subtract your age from 220.
Explanation:
option d. Ned volunteers to pick up garbage every Saturday, which helps clean up his community
The rest of the choices doesn't match what is asked. I chose option d. because by picking up garbage is of the ways that could contribute the cleanliness of the environment. Small actions bring big transcendence towards other people and in that way encourage others to take good part as well.
A paging system would be the best technological advancement for Belinda
