In any experiment, the researcher must make sure that only the __________ variable is

Bernie is eating a carrot. The sound of his chewing is drowning out the sound of his mother talking to him. Bernie is hearing this sound through __________

a) the air. b) the conduction properties of the carrot. c) bone conduction. d) the proximal auditory system.

Young children who become anxious, fearful, and angry after their parents divorce sometimes

A) require coercive discipline. B) show early signs of emotional instability. C) feel that both parents may abandon them. D) need to live with the father rather than the mother.