As the road rises, the rugged countryside becomes spectacularly barren, though plunging volcanic hillsides have been softened and greened by time.
The hillsides are full of ferns and trees.
mnli hypothesis: The hillsides are full of ferns and trees. premise: As the road rises, the rugged countryside becomes spectacularly barren, though plunging volcanic hillsides have been softened and greened by time.