(a) The complete research theory is _________ on true facts and relevant observations.
(b) Rehaan used to play second ________ for his high school's baseball team.
(c) The terrorists used the desolate industrial area as a ________ for their operations.
Base - a place from which an action can be carried out or supported /one of the four places on a baseball or rounders field that a player must touch in order to score points / a setof ideasor factsfrom which something can develop .