The prepositions used in the sentence are;
A preposition is a word that is used before a noun, or pronoun to indicate the relationship between objects, to introduce objects, and to state the time, place, and direction of something.
In the sentence above, three prepositions are used. They are;
"Through"- this shows the relationship between brainpower and alternative ideas.
"At" points to a direction while "In" introduces an object.
Summarily, the three prepositions used are through, in, and at.
Learn more about prepositions here:
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