Citizen of America is when you are born in America. Citizen of the world is when you were born out of the United States
Your pretty much rewriting your intro except now your closing your paragraph so you need to wrap everything up an tie the ends
<em><u>see (an event, typically a crime or accident) happen.</u></em>
<em><u>hope</u></em><em><u> </u></em><em><u>that</u></em><em><u> </u></em><em><u>helped</u></em><em><u> </u></em><em><u>you</u></em><em><u>!</u></em>
Answer:
One possible reason the narrator hears the sound of a heartbeat at this moment could be that he feels guilty for what he had done, so he might be hearing his own heartbeat and begin to panic, thinking that it's the old man's heartbeat he's hearing.