How to see the purity of Bellington Terrier

How can I tell if a Barrington Terrier is pure or not? A purebred Berrington Terrier has a dense coat that resembles trimmed sheep’s wool, a long head, a rounded head, a pear-shaped head, and a crown of hair on the head. The purebred Berrington Terrier has low, long, drooping ears with decorative hair at the end, small, triangular eyes, a black nose, and large nostrils. The neck should be long, the back is arched, the belly is tucked, the body shape is like a small sheep, the tail root is low, the tail is drooping. 1. 38-44 cm in height at the shoulder and 8-11 kg in weight. 2. The purebred Berrington Terrier has a long head with a rounded top and a pear-shaped head with thick crown hair, low ear roots, long and drooping ears with decorative hair at the end, small, triangular eyes, black nose and large nostrils. 4. The tail root is low and the tail droops.