A garage door opening device has a light near the floor. This light is pointed at a receiver. If a cat runs under the door while it is opening, the garage door stops moving. What property of light applies to this situation?

You find a fossil that you are sure shows evidence of bipedalism. you know this because which of the following anatomical traits is present? a. thighbones that angle in toward the knees b. a narrow pelvis c. opposable hallux d. posterior position of the foramen magnum