These fossil fuels are expensive to find and are a non-renewable resource -- that is -- there is a limited supply available on the planet.
(These fossil fuels; are; expensive to find) (These fossil fuels; to find; ) (These fossil fuels; are; a non-renewable resource -- that is) (a non-renewable resource; is; that)
These fossil fuels These fossil fuels These fossil fuels a non-renewable resource
are to find are is
expensive to find
a non-renewable resource -- that is
that