Answer:
D. absolute magnitude and apparent magnitude
When a layer of cold air close to the ground is covered by a layer of warmer air, sound waves traveling upward may be bent, or refracted, by the difference in temperature and redirected toward the ground.
Answer:
Hey shaikaadil700 !
<u> </u><u>Lubricating</u><u> </u> of rough surfaces reduces friction.
Explanation:
• Lubricating is the smoothening or polishing of the surfaces
