Answer: The earth rotates arounf the sun, and the moon rotates around the earth.
(Number 1)
Step-by-step explanation:
The question is asking you to combine these two sentences. In order to do this you can use the first sentences uses a common tool, the FANBOYS (For, And, Nor, But, Or, Yet, and So) systems to combine the two complete system. This system combines two complete thoughts such as the earth rotating around the sun and the moon rotates around the earth. If you put the commas anywhere else you change the meaning of the sentence. I hope this helps!