猫自高处跳下时,头后仰;一着地,头便前倾。猫的这些姿势变化是( )
A:耳蜗受到刺激引起的
B:鼓膜受到刺激引起的
C:半规管受到刺激引起的
D:听小骨受到刺激引起的
求证:OC是∠AOB的平分线.
下列不属于鸟类的繁殖行为的是( )
Tell your friend that you ____ ____ ____ her and you'll talk with her after class.