A daunting question about the usage of noun clauses and relative clauses (3)

Last week, we discussed the first five of the eight functions that noun clauses can perform in a sentence, namely (1) as subject, (2) as subject complement, (3) as direct object, (4) as object complement, and (5) as indirect object. This time we’ll take up the remaining three functions: (6) as prepositional complement, (7) as adjective phrase complement, and (8) as noun phrase complement.

6. Noun clause as prepositional complement that directly follows a preposition and completes the meaning of a prepositional phrase: