if blend of a land plant or vegetable are lost in a thing then that thing used to be covered by land in the surprise & a consumer is a mean of land plant ->  if fossils of trilobites are found in a place, then that place used to be covered by water in the past  if fossils of trilobites are found in a place, then that place used to be covered by water in the past & causing of resources are lost in clay & study is a mean of thing -> ohio used to be covered by water in the past