に先立って => before; prior to ~ N2
に[先立「さきだ」]って/に[先立「さきだ」]ち/に[先立「さきだ」]つ => Before A occurs/takes place N2
Time, Situation
のを知っていますか => Do you know...? N4
かも[知「し」]れない => Might A, maybe A, perhaps A N3
Sentence Endings