Answer:
The prepositional phrases are "Within minutes" and "near the Tunguska River".
Explanation:
Prepositional phrases are those phrases or groups of words that contain a preposition and an object, along with any word that modifies the object. The prepositional phrase starts with a preposition and can modify a noun or a verb.
In the given sentence, there are two prepositions used- "within" and "near". And these two prepositions also have objects in them.
Thus, the prepositional phrases in the sentence are "within minutes" and "near the Tunguska River".
