Dogs are social animals and without proper training, they will behave like wild animals. They will soil your house, destroy your belongings, bark excessively, fight other dogs and even bite you. Nearly all behavior problems are perfectly normal dog activities that occur at the wrong time or place or are directed at the wrong thing. The key to preventing or treating behavior problems is learning to teach the dog to redirect its normal behavior to outlets that are acceptable in the domestic setting.
　　One of the best things you can do for your dog and yourself is to obedience train it. Obedience training doesn’t solve all behavior problems, but it is the foundation for solving just about any problem. Training pens up a line of communication between you and your dog. Effective communication is necessary to instruct your dog about what you want it to do.
　　Training is also an easy way to establish the social rank order. When your dog obeys a simple request of “come here, sit,” it is showing obedience and respect for you. It is not necessary to establish yourself as top dog or leader of the pack (群) by using extreme measure. You can teach your dog its subordinate (从属的) role by teaching it to show submission to you. Most dogs love performing tricks for you to pleasantly accept that you are in charge.
　　Training should be fun and rewarding for you and your dog. It can enrich your relationship and make living together more enjoyable. A well-trained dog is more confident and can more safely be allowed a greater amount of freedom than an untrained animal.

　　21. Behavior problems of dogs are believe to ________.
　　A) be just part of their nature
　　B) worsen in modern society
　　C) occur when they go wild
　　D) present a threat to the community（A）

　　22. The primary purpose of obedience training is to ________.
　　A) teach the dog to perform clever tricks
　　B) make the dog aware of its owner’s authority
　　C) provide the dog with outlets for its wild behavior
　　D) enable the dog to regain its normal behavior（C）

　　23. Effective communication between a dog and its owner is ________.
　　A) essential to solving the dog’s behavior problems
　　B) the foundation for dogs to perform tasks
　　C) a good way to teach the dog new tricks
　　D) an extreme measure in obedience training（B）

　　24. Why do pet dogs love performing tricks for their masters?
　　A) To avoid being punished.
　　B) To show their affection for their masters.
　　C) To win leadership of the dog pack.
　　D) To show their willingness to obey.（D）

　　25. When a dog has received effective obedience training, its owner ________.
　　A) can give the dog more rewards
　　B) will enjoy a better family life
　　C) can give the dog more freedom
　　D) will have more confidence in himself（C）