Oil spills in large bodies of water (a) have little effect on water organisms (b) only affect life at the bottom of the water (c) can severely affect the waterfowl and other organisms living on the surface of the water (d) are not affected by tides

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas