I need help with question 2 and 3

2. Carbon-Dioxide and Nitrogen

3.After the Earth's surface had cooled to a temperature below the boiling point of water, rain began to fall for centuries. As the water drained into the great hollows and gaps in the Earth's surface, the primeval ocean came into existence.

Step-by-step explanation:

The forces of gravity prevented the water from leaving the planet.

13

step-by-step explanation:

distance formula is d=√(x2-x1)^2   +   (y2-y1)^2