Select the grading type that consists of both large and small particles but misses specific sizes.

The grading type that consists of both large and small particles while missing specific sizes is known as gap graded. Gap grading occurs when there are certain particle size ranges that are absent in the material, leading to a gap in the grading curve. This is different from well-graded materials, which contain a full spectrum of particle sizes that fit together well, and uniformly graded materials where most particles are of a similar size. Poorly graded materials have a limited range of particle sizes but do not have the characteristic gaps found in gap graded materials. Therefore, gap graded is the most accurate description for a grading type that includes both large and small particles but lacks certain intermediate sizes.