If this did not happen and all the parts of your body were not constantly repaired or replaced, you would grow old during childhood.
وإذا لم تحدث هذه العملية بحيث تُصلَح او تُستبدل باستمرار خلايا كل اجزاء جسمك ،‏ فستشيخ وأنت ما زلت بعد طفلا .‏