What keeps Mars in orbit around the Sun?
A B C D
friction gravity magnetism solar power
Question: What keeps Mars in orbit around the Sun?
(A) friction
(B) gravity
(C) magnetism
(D) solar power

Answer: (B) gravity
Answer: (D) solar power
Question: What keeps Mars in orbit around the Sun?
(A) friction
(B) gravity
(C) magnetism
(D) solar power
Answer: (B) gravity