Final answer:
The two prepositional phrases in the sentence are 'on kids' and 'to their stress levels'. They begin with a preposition and end with a noun or noun phrase.
Step-by-step explanation:
In the sentence, 'The parents' group gathered to discuss how sports may be placing unnecessary pressure on kids and contributing to their stress levels,' the two prepositional phrases are 'on kids' and 'to their stress levels'. Prepositional phrases are groups of words that begin with a preposition and end with a noun, pronoun, or noun phrase. Here, 'on' and 'to' are the prepositions, and 'kids' and 'their stress levels' are the noun phrases.
Learn more about Prepositional Phrases