Which statement best describes the role of lichens in ecological succession? A. They replace smaller trees and shrubs that need less sunlight.
B. They release acids that help break down bare rock to form soil.
C. They add nutrients to the soil and hold the soil together with roots.
D. They use nitrogen from the air to make nutrients that plants can
use.

B: They released acids to help break down bare rock to form soil.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

they are made of gases.

they have a spherical shape.

they make energy through fusion.