Question

complete the sentence.
installing rooftop solar panels has reduced my familys monthly electricity bills to practically nothing, lessened our dependence on fossil fuels, and

possibly enhanced the value of our home

could possibly enhance the value of our home

Explanation:

The sentence has a parallel structure. The first two verbs are in the past - participle form ("reduced", "lessened"). The third part should also follow this parallelism. "Possibly enhanced" (past - participle) maintains the parallel structure with "reduced" and "lessened", while "could possibly enhance" (base form of the verb) does not.

Answer:

possibly enhanced the value of our home