Over long periods of time (millions of years), pressure, bacteria, and heat changed the sediments into sedimentary rocks and the plant and animal remains into oil.
(heat; changed; the sediments; into sedimentary rocks and the plant and animal; T:Over long periods of time; T:pressure, bacteria) (heat; remains; into oil)
heat heat
changed remains
the sediments into sedimentary rocks and the plant and animal T:Over long periods of time T:pressure, bacteria
into oil