单项选择题
A．tries to criticize the false belief in precognitive experiences B．is puzzled by the mysteriousness of precognitive experiences C．provides proof for precognitive experiences D．is haunted by precognitive experiences
A．except B．because of C．beyond D．for
A. half-brain sleep has something to do with icy weather B. the mystery of half-brain sleep is close to being solved C. most birds living in cold regions tend to be half sleepers D. half-brain sleep is a phenomenon that could exist among other species