Although there are no underlined words, "Before" is a preposition. "Each" is an adjective. No other words would fit any of the four defnitions, so assume it was one of those words you were asking about.
Can You Identify The Adjective, Adverb, Preposition Or Interjection Of The Underlined Word In The Following Sentence.? I Plan To Start Writing Before Seven O'clock Each Morning.
The athlete ran swiftly down the track.