Answer:
Most of the time people enjoy long, long lives. Lots of people live well into their 70s or 80s, and some live even longer. Slowly, though, over the course of many years, the human body wears out, just like the tires on an old bicycle or the batteries in your favorite toy. When important parts of the body — like the heart or lungs or brain — wear out and stop working, the person most likely will die. When this happens, we say this person died of "old age.
