Answer:
noun
/ˈkämˌpound/
a thing that is composed of two or more separate elements; a mixture.
"the air smelled like a compound of diesel and gasoline fumes"
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adjective
/ˈkämˌpound,kəmˈpound/
made up or consisting of two or more existing parts or elements.
"a compound noun"
I think it is because you need them to separate
Whereas the beginning of the novel focuses largely on Jem and Scout's childhood and their obsession with Boo, the trial gradually begins to take over. For the first time, real racial tensions begin to emerge in the novel.