H2o goes to h3o+ a. did it gain or lose a proton? b. is it a bronsted-lowry acid or base?

             H₂O Gained Electron.

             H₂O is Bronsted-Lowry Base.

Explanation:
                   Due to amphoteric nature of water it can act as acid when reacted with strong base, also it can act as base when reacted with strong acid.
                   In given statement water is treated with strong acid hence it is acting as Bronsted-Lowery Base, as it accepting H⁺. So those species which accepts proton are called as Bronsted-Lowry Base and those which donated proton are called as Bronsted-Lowry Acid.

                                       H₂O  +  H⁺    →    H₃O⁺