the first prepositional phrase in its entirety in the space provided: In 1908, a strange fireball streaked across the sky.

In 1908 - The first prepositional phrase

Explanation:

Prepositional phrases are defined as the phrases consisting of a preposition followed by its object and any/or modifier of the object. These phrases function either as adverbs or as adjectives in a sentence by providing information to modify a noun or verb.

In the given sentence, the first prepositional phrase 'In 1908' is at the very beginning of the sentence. It consists of the preposition 'on' followed by the object '1908.' It functions as an adverb in the sentence and qualifies the verb 'streaked' by providing information about the time(when) the action took place.