The message Huck finds inside the Bible that Sophia Grangerford has asked him to retrieve from the church is an example of understatement
Explanation:
An understatement is a phrase that describes something as not important or that reduces the importance of an event or information, then the little paper that says “Half-past two” seems to have no importance to Huck but later he discovered that it was a big deal in fact since the events that happened because of that paper really disturbed him.
In this sentence, "which lasted two hours" is an adjective clause because it describes the school play by telling how long it lasted. Also, adjective clauses often start with words such as "who", "that", "which", or "when", along with others.