Explanation:
There is approximately 100 billion galaxies known to be there..
read the directions carefully
my dear you got the idea :)
in my opinion
Adjectives and Adverb phrases relate to prepositional phrases because if you remember what an adjective is, it describes a noun and then an adverb i believe can describe a verb, adjective, and other adverbs. Both adjective and adverb phrases contain prepositions, there fore relating them to prepositional phrases.... I hope this is what you were looking for and answered your question... :)