Reflection of light: The moon reflects sunlight.
Mechanical motion: the moon falls with the ground as a reference.
Sound production: The crow's vocal cords vibrate to produce sound.
Transmission of sound: Sound can spread in the air, making people hear crows.
Formation of frost (or fog): Water vapor in the air condenses at night to form frost (or fog).
Refraction of light: The night view observed by human eyes is equivalent to convex lens imaging.