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

　　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

　　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

　　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.

　　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

　　Passage Two

　　Questions 26 to 30 are based on the following passage:

　　Engineering students are supposed to be examples of practicality and rationality, but when it comes to my college education I am an idealist and a fool. In high school I wanted to be an electrical engineer and, of course, any sensible student with my aims would have chosen a college with a large engineering department, famous reputation and lots of good labs and research equipment. But that’s not what I did.

　　I chose to study engineering at a small liberal-arts（文科）university that doesn’t even offer a major in electrical engineering. Obviously, this was not a practical choice; I came here for more noble reasons. I wanted a broad education that would provide me with flexibility and a value system to guide me in my career. I wanted to open my eyes and expand my vision by interacting with people who weren’t studying science or engineering. My parents, teachers and other adults praised me for such a sensible choice. They told me I was wise and mature beyond my 18 years, and I believed them.