Which statement about earth's layers is true?
oa.
they all consist of liquid rock.
b.
they each vary in size and temperature.
c. they are all under an equal amount of pressure.
d. they will soon combine, forming a single, thick layer.

B

Explanation:

The do vary in size and temperature because as the layers go down to the core it gets harder and magma is more present

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]