Do you like dogs? As the saying goes, "Dogs1 man's best friends." And this animal has been good friends2 human beings for thousands of years. In China today,3 people keep dogs as their pets in the city. In the countryside, people keep dogs 4 doors of their houses. The army or police also keep dogs, but for different working purposes.
Crime (犯罪活动) sometimes takes place in the society. Police dogs have an important role in fighting crime. Each dog 5 with one police officer. Together, the dog and the officer go through a6 program of difficult training. From the training, the dog can learn many skills.7 will help it a lot in its future tasks. After the dog8 , it will use its super-powerful nose to help the officer look for criminals, search for stolen things and sniff (嗅) out something dangerous and illegal*. A police dog and its human partner always work9 as a team. They stay together almost all the time.
This explains 10 good helpers to people.
* The word "illegal" means not allowed by the law.
