When you move material across the cell membrane from an area of high concentration to an area of low concentration.

1. Passive Transport
2. Active Transport

Passive Transport

Explanation:
When rolling a wagon up a hill, it would require more energy (activity) to get to the top; this is similar to moving from a low concentration to a higher. When rolling down a hill with a wagon, it would be more easy (passive); this is similar to moving from high to low concentration.

They formed the oceans.  as they melted water was formed and the water made the oceans