Answer:
repetitive force
Explanation:
repetitive forces like jumping up and down
and running long distances which cause tiny cracks in the bone.
What is the subjecy bc i migjt know
<span>I believe tetralogy of fallot is a DQ from military service because some of its symptoms can be found in the list of DQs related to the heart.</span>
The answer to your question is,
Endorphins. :)
-Mabel <3
