他们 / 蓄谋 / 在 / 节假日 / 发动 / 袭击 / 但 / 计划 / 已 / 被 / 警方 / 掌握他们蓄谋在节假日发动袭击,但计划已被警方掌握。They plotted to launch an attack during the holiday, but the plan has already been discovered by the police.