The phrase "a normal surface" is correct and usable in written English.
It can be used in contexts related to geometry, mathematics, or discussions about physical properties of surfaces.
Example: "In geometry, a normal surface is defined as one that is flat and does not exhibit any irregularities."
Alternatives: "an ordinary surface" or "a standard surface".
Crabs took the same number of steps as if they were on a normal surface, but since they made no progress with some of the steps they ended up short of their burrow.
This property is significant because sediment may be transported and deposited farther down fan in the confines of a trench than it would be in a normal surface channel.
Had it been a normal surface it would have been alright, but down there it was impossible".
(7) The fifth metatarsal bone can appear with a normal surface (unaffected) or with periostitis or exostoses or shortened and deformed [14].
The curve which is the lowest on the right part of the graph represents the irradiance directly hitting a normal surface for a mid-latitude summer location in the United States.
A normal surface rupture zone ~10 km in length predominantly emerged along the previously mapped 7-km-long Idenokuchi fault (Research Group for Active Tectonics in Kyushu 1989, Fig. 1).
Then, a 2D normal surface image is defined by projecting the 3D PCD along a selected normal vector.
This is in contrast to the situation of neutron stars that have a more normal surface.
A piece of glass that has one half with a normal flat surface, and the other with the new patterned surface, demonstrates the anti-fogging properties that the patterning provides.
If the organizers of the Madrid Open did not go back to a normal clay surface next year, "it will be one less tournament in my calendar," he said.
It promises to be a normal Melbourne surface.
