The biosphere is the part of Earth where life exists, extending from the ocean floor to the lower atmosphere. It includes all living organisms and their interactions with the environment.
The layer below the continents and the ocean floor is the Earth's mantle. It is a solid layer of rock that extends about 1,800 miles (2,900 kilometers) beneath the Earth's surface. The mantle is responsible for the movement of tectonic plates and drives processes like earthquakes and volcanic eruptions.
sea floor spreading
The Continental Shelf ; see related link below .
Lingual frenum
The ocean ridge.
The thin fold of mucous membrane that extends from the floor of the mouth to the underside of the tongue is called the lingual frenulum. It helps to limit the movement of the tongue and is involved in speech and eating functions.
The floor of a fireplace is typically called the hearth. It is a heat-resistant material such as brick, stone, or tile that surrounds the fireplace opening and extends into the room to protect the floor from heat and sparks.
It is the continental shelf.
Argon is a naturally occurring element.It is not chemically reactive and is heavier than air - so your argon balloons will sit on the floor not the ceiling!
Pits could be made indoors with a cushion and carpet floor or the earth pit which has no floor and the pit is made of earth and dirt.
The urethra drain the bladder to the exterior of the body.