（) When we say dogs are friends of humans, we usually think of them as a mental abstraction.

When we use a word in speech and writing, its most obvious purpose is to point to some thing or relation or property. This is the word's" meaning."

Let us suppose that the one grandparent of the dog was a collie, another was an Irish terrier, another a fox terrier, and the fourth a bulldog. We can express these facts equally scientifically and objectively by-saying that he is a dog of mixed breed. We have in no way gone be yond the requirements of exact scientific description.

Suppose, however, that we had called the same animal a" mongrel". The matter is more complicated. We have used a word which objectively means the same as" dog of mixed breed", but which also arouse in our hearers an emotional attitude of disapproval toward that particular dog. A word, therefore, can not only indicate an object; but can also suggest an emotional attitude toward it. Such suggestion of an emotional attitude does go beyond exact and scientific discussion because our approvals and disapprovals are individual--they belong to ourselves and not to the objects we approve or disapprove of.

Once we are on the outlook for this difference between" objective" and "emotional" meanings, we shall notice that words which carry more or less strong suggestions of emotional attitudes are very common and are ordinarily used in the discussion of such debatable questions as those of politics, morals, and religion. This is one reason why such controversies cannot yet be settled.

There is a well-known saying that the word "firm" can be declined as follows: I am firm, you are obstinate, and he is pigheaded. This is a simple illustration of what is meant. "Firm," "obstinate", and "pigheaded" all have the same objective meaning--that is, following one's own course of action and refusing to be influenced by other people's opinions. They have, how ever, different emotional meanings:" firm" has an emotional meaning of strong approval, "obstinate" of mild disapproval, "pigheaded" of strong disapproval.

In much the same way when, during World War I , thoughts were dominated by emotions, the Americans contrasted the spirit of our heroic boys with ruthlessness of the Germans. Now with the more objective attitude that has been brought by the lapse of time, we can look back and see that the spirit and the ruthlessness are objectively the same. Only the one word has an emotional meaning of approval, the other of disapproval.

The first three paragraphs tell us that______.

A．there is no real difference between calling a dog a mongrel and calling it a mixed breed

B．a dog of mixed breed is an emotional term

C．mongrel is an objective term

D．words may suggest emotional attitude as well as objective meaning

Study Says Dogs Can Smell Cancer

Dogs are known for their sense of smell. They can find missing people and things like bombs and illegal drugs. Now a study suggests that the animal known as man's best friend can even find bladder(膀胱)cancer.

Cancer cells are thought to produce chemicals with unusual odors(气味). Researchers think dogs have the ability to smell these odors, even in very small amounts, in urine(尿). The sense of smell in dogs is thousands of times better than in humans.

The study follows reports of cases where, for example, a dog showed great interest in a growth on the let of its owner. The mole(痣)was later found to be skin cancer.

Carolyn Willis led a team of researchers at Amersham Hospital in England. They trained different kinds of dogs for the experiment. The study involved urine collected from bladder cancer patients, from people with other diseases and from healthy people.

Each dog was tested eight times. In each test there were seven samples for the dogs to smell. The dog was supposed to signal the one from a bladder cancer patient by lying down next to it.

Two cocker spaniels(短腿长毛垂耳小猎犬)were correct fifty-six percent of the time. But the scientists reported an average success rate of forty-one percent.

As a group, the study found that the dogs chose the correct sample twenty-two out of fifty-four times. That is almost three times more often than would be expected by chance alone.

The British Medical Journal published the research. In all, thirty-six bladder cancer patients and one hundred and eight other people took part.

During training, all the dogs reportedly even identified a cancer in a person who had tested healthy before the study. Doctors found a growth on the person's right kidney(肾).

Bladder cancer is the ninth most common cancer worldwide. The International Agency for Research on Cancer says this disease kills more than one hundred thousand people each year. Doctors say cigarette smoking is the leading cause of bladder cancer.

The experiment was conducted in a

A．private home.

B．training school.

C．hospital.

D．police station.

回答题：

Study Says Dogs Can Smell Cancer

Dogs are knowrn for their sense of smell. They can find missing people and things like bombs and illegal drugs. Now a study suggests that the animal known as man&39;s best friend can even find bladder(膀胱) cancer.

Cancer cells are thought to produce chemicals with unusual odors(气味). Researchers think dogs have the abilit)to smell these odors, even in very small amounts, in urine(尿). The sense of smell in dogs is thousands of times better than in humans.

The study follows reports of cases where, for example, a dog showed great interest in a growth on the leg of its owner. The mole(痣)was later found to be skin cancer.

Carolyn Willis ted a team of researchers at Amersham Hospital in England. They trained different kinds of dogs for the experiment. The study involved urine collected from bladder cancer patients ,from people with other diseases and from healthy people.

Each dog was tested eight times. In each test there were seven samples for the dogs to smell.

The dog was supposed to signal the one from a bladder cancer patient by lying down next to it.

Two cocker spaniels(短腿长毛垂耳小猎犬) were correct fifty-six percent of the time. But the scieatists reported an average success rate of forty-one percent.

As a group, the study found that the dogs chose the correct sample twenty-two out of fifty-four times. That is almost three times more often than would be expected by chance alone.

The British Medical Journal published the research. In all, thirty-six bladder cancer patients and one hundred and eight other people took part.

During training, all the dogs reportedly even identified a cancer in a person who had tested healthy before the study. Doctors found a growth on the person&39;s right kidney(肾).

Bladder cancer is the ninth most common cancer worldwide. The International Agency for Re-search on Cancer says this disease kills more than one hundred thousand people each year. Doctors say cigarette smoking is the leading cause of bladder cancer.

The experiment was conducted in a __________. 查看材料

A.police station

B.hospital

C.training school

D.private home

听力原文： Animals perform. many useful and entertaining jobs. Dogs are particularly valuable in guiding the blind, protecting property, finding lost people, and hunting criminals. Horses are used in guarding herds, carrying men in lands when there are no roads and helping farmers work on their lands.

Dogs are extremely useful as companions for blind people. When a dog has been properly trained, he will al ways lead its blind master in the right direction and keep him out of danger. For instance seeing-eye dogs learn never to cross a busy road when cars are coming, even if their masters command them to do so.

Horses are also able to learn lots of things. Horses used for guards or police duty must learn never to be frightened of noises, traffic and other disturbances. Racing horses are able to learn much faster than other horses. Therefore it is necessary for those who train them to be very patient and understanding.

Pigeons have a natural instinct to return home, even if they are far away and the trip is very hard and dangerous. Men utilize this instinct to send messages on small pieces of paper that are fastened to the pigeon's back or legs. In wartime, pigeons have been known to fly as fast as 75 miles an hour and to cover distances of 500 to 600 miles.

What can we infer from the passage?

A．Dogs have a natural instinct to return home.

B．Seeing-dogs sometimes may not obey its master.

C．Dogs are kept mostly as companions for old people.

D．Guarding dogs always nm fast.

We all love a hero, and rescue dogs are some of the biggest heroes of all. You will often find them going above and beyond duty to save someone, risking--and at times losing--their lives in the process.

Rescue dogs are generally found in the Sporting and Hunting Groups, or from the traditional Herding Group. These types include the Bloodhound, Labrador Retriever, Newfoundland, German Shepherd, Golden Retriever, and Belgian Malinois--all of which are chosen for search-and-rescue duty because of their amazing physical strength, loyalty, and their tendency for mental stability.

These types also have a keen sense of hearing and smell--to better locate lost individuals—and are often able to access hard-to-reach areas. As highly trained animals, they serve in many different fields, including specialist search, snow slide rescue, dead body location, and tracking.

To overcome obstacles and succeed when performing the demanding duties of a search-and-rescue worker, a dog must display certain qualities. In addition to intelligence and strength, the dog must be swift, confident, easily trainable, adaptable, and have a high level of stamina (耐力) and endurance. A strong sense of group cooperation and an ability to engage in friendly play during "down" time is also required of search-and-rescue dogs.

A rescue dog goes through many, many hours of intensive training to be fit for duty. Training is not for the faint-hearted. Certification training can take from two to three years, working three to four hours a day, three to six days a week, often in group,team-oriented sessions.

Each search-and-rescue field requires different types of training. Rescue training, for instance, includes "air scenting"--where dogs are trained to smell the air for the victim&39; s scent (气味) and then follow the scent to the person. This ability is crucial to finding victims trapped under collapsed buildings and snow slide.

40. Rescue dogs are chosen probably because__

A.they are loyal

B.they are brave

C.they have amazing appearances

D.they have good eyesight

What does "faint-hearted" in Paragraph 5 mean?A.Courageous.

B.Cowardly

C.Energetic

D.Slow

Which ability is most important for dogs to rescue people trapped in snow?A.Sharp hearing

B.Swift movement

C.Extraordinary smelling

D.A strong memory

What is the passage mainly about?A.Selection process of rescue dogs

B.Qualities and training of rescue dogs.

C.Risks rescue dogs are faced with

D.Types of tasks rescue dogs can perform

请帮忙给出每个问题的正确答案和分析，谢谢！

听力原文： Animals perform. many useful and entertaining jobs. Dogs are particularly valuable in guiding the blind, protecting property, finding lost people, and hunting criminals. Horses are used in guarding herds, carrying men in lands when there are no reads and helping farmers work on their lands.

Dugs are extremely useful as companions for blind people. When a dog has been properly trained, he will always lead its blind master in the right direction and keep him out of danger. For instance seeing-eye dogs learn never to cross a busy read when cars are coming, even if their masters command them to do se.

Horses are also able to learn lots of things. Horses used for guards or police duty must learn never to be frightened of noises, traffic and other disturbances. Racing homes are able to learn much faster than other horses. Therefore it is necessary for those who train them to be very patient and understanding.

Pigeons have a natural instinct to return home, even if they are far away arid the trip is very hard and dangerous. Men utilize this instinct to send messages on small pieces of paper that are fastened to the pigeon's back or legs. In wartime, pigeons have been known to fly as fast as 75 miles an hour and to cover distances of 500 to 600 miles.

What can we infer from the passage?

A．Dogs have a natural instinct to return home.

B．Seeing-dogs sometimes may not obey its master.

C．Dogs are kept mostly as companions for old people.

D．Guarding dogs always run fast.