The Ocean

The ocean floor —

• is always a flat bed of sand

• has mountains, plains, and ridges like land surfaces

• is covered by the same amount of water everywhere

• covers less area than the land

Which location is likely to have the greatest water pressure, the coldest temperatures, and the smallest number of living organisms?

• 1

• 2

• 3

• 4

Which best describes the part of the ocean called the continental shelf?

• A flat underwater valley

• A region of mountains in the deep ocean

• A shallow area of sediment near the shore

• A region with a higher water pressure

Which of these are the deepest parts of the ocean?

• Continental shelves

• Continental slopes

• Ocean trenches

• Abyssal plains

The diagram shows a model of the ocean floor. Which number identifies the continental slope?

• 1

• 2

• 3

• 4

At which location

are oceans the deepest?

• Mid-ocean ridge

• Abyssal plain

• Ocean trench

• Volcanic island

The main difference between ocean water and lake water is that ocean water contains —

• oxygen

• salt

• algae

• plants

Which of these increases as a submarine dives deeper into the ocean?

• The number of plants in the water

• The freshness of the water

• The water temperature

• The water pressure

The salinity of the Mediterranean Sea is greater than that of the Atlantic Ocean. This means that, compared to the Atlantic Ocean, the Mediterranean Sea is —

• wider

• deeper

• saltier

• cooler

The most important reason that lakes and oceans have different types of animal life is that oceans have

• sandy shores and bottoms

• water with more salt

• large waves at the edges

• a much larger surface area