Answer:
Explanation:
A colon should only be used if the sentence before the colon is an independent and complete thought. The colon should be able to be replaced by a period and the information after the colon removed
The summary of what happened is right here: https://www.sparknotes.com/lit/gatsby/section7/
The Communist Manifesto by Karl Marx and Friedrich Engels ends with the phrase "Workers of all countries, unite!"