Can someone please help me i am in need of some assistance Which statement best describes the role of lichens in ecological succession?

A. They replace smaller trees and shrubs that need less sunlight.

B. They add nutrients to the soil and hold the soil together with roots.

C. They release acids that help break down bare rock to form soil.

D. They use nitrogen from the air to make nutrients that plants can use.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

not only is it colder, it also becomes darker, less salty, and more dense.