SRL for [locked out]: Those massive structures , while posing cost and environmental headaches , effectively [locked out] all but deep - pocketed giants from steelmaking .
ARG-0: Those massive structures | ARG-M-ADV: while posing cost and environmental headaches | ARG-M-MNR: effectively | ARG-1: all but deep - pocketed giants | ARG-2: from steelmaking