36. It was good __________ Mira to help me. She has her own problems.*offofonwith

The correct word to fill in the blank is "of."

The complete sentence reads: "It was good of Mira to help me. She has her own problems."

Explanation

The preposition "of" is used here to indicate that it was commendable or admirable for Mira to assist someone despite her own challenges. This expression acknowledges her kindness and selflessness, recognizing that she prioritized helping another person even when she had her own issues to deal with. Prepositions like "on," "with," and "off" do not fit contextually in this sentence because they do not convey the sense of worthiness or commendation that "of" does.

In summary, the most suitable choice here is "of," which appropriately conveys the speaker's appreciation for Mira's help.