Due to it's great size, China is a land of contrast.
Answer:
Precession
Explanation:
Various stars will act as northern stars due to precession, as well as the stars and planets arrayed around the celestial equator (zodiac) will steadily change locations. Every 73 years, they move around one degree. For the remainder of our days, and for a few millennia later, Polaris would stay the North Star.
The largest and most important river system in South America is the Amazon. Making A your answer.
