Question: What are bisexuals taking part in the LGBT pride parade are celebrating?
Sentence (from "Tucson Pride"): Tucson Pride organizes and promotes the greater Tucson metropolitan areas LGBT pride parade ("Pride on Parade") and pride festival ("Pride in the Desert") which are currently held at the start of October each year in Tucson, Arizona, to celebrate the lesbian, gay, bisexual, and transgender (LGBT) community and their allies.
Relevant evidence: Yes