Conditioned stimulus is a stimulus that makes the organism react to something associated to something else. In this case it made the dogs salivating at the sight of the person that brought them food because that person was the person that fed them.
In order for CS to happen, it requires repeated stimulation over time.
Food contamination can occur in many different ways. Four main causes of food contamination are: 1. Not washing hands 2. Cross-contamination 3. Improper storage and cooking temperatures 4. Contamination by animal waste
