In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant. 

Minerals fill spaces between bits of sediment. The sediments become glued together. The glued together parts become hard like cement. The sediment becomes a big rock. The rocks erode slowly. The rocks come apart. The rocks become smaller rocks. The rocks continue to erode into smaller rocks. The process starts again. 
minerals ,sediment ,big rock; rocks ,smaller rocks 

The cornea and lens refract light into a small image. Shine it on the retina. The retina's rods and cones convert it to electrical pulses. The optic nerve carries electrical pulses through the optic canal. Nerve fibers end in the lateral geniculate nucleus and the visual cortex. 
light ,small image ,retina's rods and cones ,electrical pulses 

A plant dies. Bacteria from the ground migrate to the plant material. Bacteria release enzymes onto the plant material. The enzymes break down the plant cells to simpler components. The bacteria absorb the resulting components. 

bacteria ,enzymes ,plant cells ,components