Answer:
C <em>cycling</em>
Explanation:
I'm saying cycling because everyone learned how to ride a bike at a young age and even if you don't know how to ride, you can put on training wheels. (lol). Hiking could be another good alternative but in case you get worn out, theres no place to call to get picked up because of bad service.
Answer:
D
Explanation:
Because substance abuse is a Health problem
What property makes the normal pacemaker region of the heart function as a pacemaker?
The property of the normal pacemaker region is able to provide a normal setting for the heart to beat. It allows the heart to beat at a regular rate.
For preventing stds use a condom birth control or abstinence
If organ systems failed to work together your body would not work because your heart pumps blood in order for your whole body to work.