The prepositions in the sentence are;
A preposition is a part of speech that is typically used before a noun phrase, a noun, or pronoun to indicate a direction, location, or duration of something. They also show the relationship between words in a sentence. In the sentence given above, the prepositions are; through, about, and for.
'Through' indicates the way critical thinking can be used to obtain a positive effect. 'About' is another preposition that means 'concerning' or 'regarding'. 'For' is the third preposition that indicates the end result of something.
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