C. one complete spin on its axis because the rotation is referring to the planet's period of rotation. D is called a revolution. B determines the seasons on the planets. A is called an ellipse.
Answer:
B
Explanation:
there moving the waves through energy
Answer:
YES
Explanation:
An echo may be defined as a sound which is repeated because of the sound waves that are produced are reflected back after striking a surface. Sound waves can smoothly bounce off the hard objects in the same manner as a rubber ball bounces back the ground.
When a sound wave strikes a hard surface, the sound waves gets reflected back and bounces back to the observer and produces an echo. If the sound waves strikes a soft surface it absorbs the sound.
Although the direction of a sound changes but the echo sounds in the same way as the original sound.
