Final answer:
It is important to let the chest come back to its normal position after each compression in CPR to allow the heart to refill with blood.
Step-by-step explanation:
The chest should come back to its normal position after each compression in cardiopulmonary resuscitation (CPR) because it allows the heart to refill with blood before the next compression. When the chest is compressed during CPR, blood is squeezed out of the heart and into the circulation. Releasing the pressure on the chest allows the heart to expand and refill with blood, ensuring that a continuous flow of oxygenated blood is provided to the brain and other vital organs.