The earths rotation. The earth rotates and as it rotates, the sun moves across the sky
The appropriate answer is d. recording and studying seismic waves. Seismic waves behave differently as the enter the different layers of the Earth. Scientists used seismic or earthquake waves to determine the different layers of the Earth. The behaviour of the waves as they move through the layers helped scientists identify the boundaries and the state of each layer; solid or liquid.
Answer:
I'd say it's the number of water drops.
Explanation:
The number of water drops is what you're controlling or purposely controlling and that answer choice makes the most sense out of the other answer choices. So I'd say it's "The Number of Water Drops."
