sentences: an ocean plant is a kind of water plant & if year of a land plant or vegetable are lost in a thing then that thing used to be covered by land in the surprise ->  if fossils of ocean plants are found in a place then that place used to be covered by water in the past  if fossils of ocean plants are found in a place then that place used to be covered by water in the past & a sea is a mean of thing & a fossil of an ocean plant is found in the desert -> the desert used to be covered by water in the past