For instance, when training the dog for scenting out drugs, trainers start with large quantities of drugs and let the dog become familiar with the scent. Gradually the amounts are diminished and the dog's sense of smell becomes more sensitive to the scent of the contraband.
以毒品犬的訓練過程而言，先讓它嗅聞有強烈味道的毒品，然後逐漸降低毒品份量，每次聞後都要它靜臥不動。