The first one should be mM
I think that since it lives on the ocean floor, at the deepest of the ocean. So anyway, the fin on the Eurypterids is still necessary but not that much, since they live on the ocean floor. Their movements mostly on the ocean floor. So fin would not help them "stick" to the floor. Also there are still gravity acts on the Eurypterids and the feet would help them move faster. Hope this helps.
Cellulose is found in the cell walls of plant cells. It is permable so any substance disolveabls in water can pass through so it dose not act as a barrier. It gives the cell its strength and support. As water moves in to the cell by osmosis it stops the cell from bursting.
Yes our lungs will be clean and perfect.