Soil Horizon

Which of the soil layers in the picture is the C horizon?

• A

• B

• C

• D

Topsoil layer (O) that has humus is good for planting trees because it has a lot of________ matter.

• inorganic

• organic

• chemical

• mineral

What is the last paragraph mainly about?

• Thickness of each soil layer depends on humidity, geologic at processes and the depth of the B horizon.

• Thickness of each soil layer depends on topography, geologic at processes and the depth of the B horizon.

• Thickness of each soil layer depends on topography, geologic at processes and the depth of the C horizon.

• Thickness of each soil layer depends on humidity, geologic at processes and the depth of the C horizon.

Which is the best title for the passage?

• Soil layers

• Soil types

• Soil structure

• Soil conservation

The word ‘excavate’ means __________.

• to dig a hole

• to plant a tree

• to make a pottery

• to measure humidity