No it does not have to be smooth.
smooth surface.
on a smooth surface
jagged
Smooth surface
The leaves of Betula populifolia are smooth on the lower surface.
The rough surface is better than the smooth surface for the frictional force to act.
The surface of electric machine are smooth why
It is not smooth it has craters
Yes it is smooth
Here we are talking about the surface of the muscles..... Smooth muscles have smooth surface while striated muscles have rough surface.....
Smooth
smooth surface