What is a monopoly and how does this type of business operate

Why might it be important to know a currency’s exchange rate

In ohio in 1872, the cleveland massacre was a)a violent labor dispute at standard oil refineries in cleveland. b)a takeover by standard oil of the refineries in cleveland. c)an attempt to stop standard oil from becoming a monopoly. d)a failed attempt by standard oil to take over other refineries.

Is harry truman considered a hero or a tyrant for dropping the atomic bombs on hiroshima and nagasaki? (need a paragraph)