The river forms a natural line between the north and south sections of the city.
In fact, if many of the "natural" lines were straight, we would then wonder why?
But this river is a natural line of defense.
"We realized that these songs seemed to draw a natural line under the last 31 years of our working together."
He'd be glad when he could let his hair grow back in its natural lines again.
As the doctor says, it follows the natural lines of a woman's figure.
Magical energy is created by living things and runs along natural lines, like water.
Use the natural line in the middle of the body as a marker.
She held it about six inches from Web's face and above his natural line of sight.
There are no longer enough natural lines to support their population.