Dogs are easy to educate. Well-educated dogs are sometimes used as watchdog?s __________. It is interesting, though, that these dogs, which can become terrifyingly wild in times of danger, pose no harm to their owners. In the face of a threat, they put their lives in danger to save their owners.

• A. There are hundreds of dog species of different colours and sizes
• B. A watchdog can stop a creature that is five to six times bigger
• C. Dogs have 42 teeth, that is, 10 more than human beings
• D. They were able to perceive moving objects from farther away