A primary source. A primary sources are first hand accounts like diaries, autobiographies, etc.
Answer: The gravity of the Sun
Explanation: The gravitational pull of the sun is strong enough to keep the planets rotating.
Answer:
The Gupta Empire stretched across northern, central and parts of southern India between c. 320 and 550 CE. The period is noted for its achievements in the arts, architecture, sciences, religion, and philosophy
Explanation:
explanation in text
