GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - Y4658BICQS6WR15SJ

According to the passage, the immobilization hypothesis fails to account for which of the following facts? A. That sleep does not appear to be a uniform and unchanging state B. That under certain conditions animals appear to need more sleep than usual C. That animals rarely sleep when a predator has been detected nearby