Water molecules presently in the oceans flowed into the ocean early in the history of the Earth and have remained there for most of the history of the planet.
(Water molecules; flowed; into the ocean; T:early in the history of the Earth; T:presently; T:in the oceans) (Water molecules; have remained; there; T:for most of the history of the planet)
Water molecules Water molecules
flowed have remained
into the ocean T:early in the history of the Earth T:presently T:in the oceans
there T:for most of the history of the planet