由先行词awareness引导的同位语从句（that they were being experimented upon）
主语：An awareness
谓语：seemed
宾语：to be enough to alter workers' behavior by itself
定语：were being experimented upon
状语：by itself
补语：to alter workers` behavior by itself
译文：一种充当试验品的意识足以使工人们的行为举止发生变化~