What are two parts of the peripheral nervous system

The peripheral nervous system (PNS) has two components: the somatic nervous system and the autonomic nervous system. The PNS consists of all of the nerves that lie outside the brain and spinal cord

Explanation:

the answer to your question is b

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

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bioteacher101