Animals can perform many useful and entertaining jobs. People realize animals may not have the same intelligence as much human beings. They are clever enough to learn many things. For example, dogs can particularly of valuable in guiding the blind, protecting property, finding lost people and hunting animals. It's not very difficult to learn some easy commands such as "sit, lie down, stay here, come here, bring clothes "and so on. Training a dog to be a watchdog often produces un -expected results. some dogs quickly know the difference between strangers and friends because their masters welcome friends and invite them into their houses, and sometimes dogs always attack the postman who comes to deliver letters. One explanation for this behavior is that the postman comes to the house often. He never enters the house and so the dog thinks the postman is not wanted. Horses are also able to learn many thHorse. Horses are used for guard or police duty must learn never to be frightened of noises, traffic and other disturbances. Racing horses are able to run much faster than other horses. Some dogs may become suspicious of postman because postman___