These large bodies of water are covered with sand and rock, located inland, and usually fed by a stream.
1. pond

2. lake

3. cave

4. river

The answer is 2; Lake.

Explanation:

A lake (from Latin lacus) is a large body of water (larger and deeper than a pond) within a body of land. As a lake is separated from the ocean, it is not a sea. Some lakes are very big, and people in the past sometimes called them seas. Lakes do not flow like rivers, but many have rivers flowing into and out of them.

not: both offer magnification to the atomic level.