Answer: Place the refuse down the garbage chute.
Step-by-step explanation:
A preposition is a pary of speech that is typically used before either a noun, or pronoun, to show the place, direction, time, or location. Examples of prepositions are words like down, to, of, in, at, etc.
The sentence whereby the underlined word is a preposition is "Place the refuse down the garbage chute". Here, the underlined word which is "down" comes before the noun.