Question

a body of water completely surrounded by land *
choose
mountains
plain
valley
lake
oceans

Explanation:

A lake is a body of water completely surrounded by land. Mountains are large landforms that rise prominently above their surroundings. A plain is a flat, relatively level area of land. A valley is a low area between hills or mountains. An ocean is a very large body of salt - water that covers most of the Earth's surface.

Answer:

Lake