GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 135F74WUPY3H5T16A

One big challenge with placebo responses is that they are ____________: people given the same inert pill or potion may show wildly different reactions, and the effects vary widely according to each person's illness. A. capricious B. illusory C. unpredictable D. chimerical E. marginal F. ephemeral