Plant roots break up the surface of a rock allowing water to penetrate the cracks.
(Plant roots; break up; the surface of a rock) (a rock; allowing; water to penetrate the cracks) Context(a rock allowing,List([36, 51))):(water; to penetrate; the cracks)
a rock allowing,List([36, 51))
Plant roots a rock water
break up allowing to penetrate
the surface of a rock
water to penetrate the cracks
the cracks