Ineed with question 15 and it’s very hard and i’m struggling with it and if you need to see the picture big then click on it and it will be big

I would say from the sun so #3 

Processes above and be sure to mention the movement of electrons and energy as the carbon atom moves from one reaction to another.

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution