Due to collisions between particles in the spinning cloud, the solar nebula begins to flatten. The particles in the gas cloud first have all different speeds in different directions. As they start colliding with each other, their final velocity is the average of the two initial velocities before collision.
Answer:
bcz lichens grow only there have no pollution and new ecosystem have no pollution in this way lichen are necessary after disturbances bcz after pollution have created by human
Athletics would be the easiest choice here
Sports are an active that takes up a lot of different organ systems. When running I use my muscular system and cardiovascular system the most. The cardiovascular system directly controls running because it helps prevent me from getting tired and worn out faster.
Hope this helps :)
