Earth's Oceans Test

Most organisms that perform photosynthesis live in the _____________.

• Trenches
• Abyssal Plains
• Surface Zone

___________ are the deepest part of the ocean.

• Abyssal Plains
• Trenches
• Mid-Ocean Ridges

On average, the salinity of seawater is 55 parts per thousand.

• True
• False

____________ are large, flat areas of the seafloor that are covered in sediment.

• Abyssal Plains
• Trenches
• Mid-Ocean Ridges

How did ocean water become salty?

• It mixed with methane hydrates.
• Rain dissolved minerals from rocks.
• Volcanoes erupted water vapor into the air.

Earth's oceans formed when rain filled deep basins on Earth.

• True
• False

Asteroids and comets might also have added water to the oceans.

• True
• False

Manganese nodules are mineral resources from the ocean floor.

• True
• False

Evaporation in polar regions causes surface water to become saltier.

• True
• False