At the minimum, a prepositional phrase will begin with a preposition and end with a noun, pronoun, gerund, or clause, the "object" of the preposition. In = preposition; the, weedy, overgrown = modifiers; garden = noun.
segregatipn started and the civil rights act
You can try starting with a question, fact, or sound affect to help grab a reader's attention, but it should fit well with your topic.
3D printing is incredibly resource efficient since the only material consumed is what passes under the laser (or through the extruder, etc.), whereas traditional manufacturing requires the use of extra materials (molds for injection molding, scraps for perforated sheet metal assembly, etc.)
Turkey's is the possessive noun
