Question

be sure to place your phone in the cell phone lock box every day. interjection pronoun conjunction preposition

Explanation:

The word "IN" in the sentence "Be sure to place your phone IN the cell phone lock box every day" is a preposition. Prepositions show the relationship between a noun (or pronoun) and other words in a sentence, often indicating location, time, or direction. Here, "IN" indicates the location where the phone should be placed (inside the lock box). The other options: interjection (expresses emotion, e.g., "Oh!"), pronoun (replaces a noun, e.g., "he"), conjunction (connects words/phrases/clauses, e.g., "and") do not fit the function of "IN" here.

Answer:

preposition