This means scientists can date rock which is many millions of years old.
(rock; is; many millions of years old) (This; means; scientists can date rock) Context(This means,List([0, 10))):(scientists; can date; rock which is many millions of years old)
This means,List([0, 10))
rock This scientists
is means can date
many millions of years old
scientists can date rock
rock which is many millions of years old