Dogs have an understanding of fair play and become angry if they feel that another dog is getting a better deal, a new study has found.
The study looked at how dogs react when a companion is rewarded for the same trick in an unequal way. Friederike Range, a famous researcher, and her colleagues did a series of experiments with dogs who knew how to respond to the command “give the paw”. The dogs were normally happy to repeatedly give the paw, whether they got a reward or not.
But that changed if they saw that another dog was being rewarded with a piece of food, while they received nothing. The dogs hesitated significantly longer when obeying the command to give the paw. Eventually, the unrewarded dogs stopped cooperating.
Researchers always assumed that only humans pay close attention to unfairness. That changed in 2003 when Frans De Waal, a professor of psychology, and a colleague named Sarah Brosnan did a survey on monkeys. Monkeys had to hand a small rock to researchers to get a piece of cucumber(黄瓜) in return. However, the monkeys would suddenly become angry when receiving the piece of cucumber if they saw another monkey receive a more delicious reward, such as a grape, for doing the same job. The monkey that got the cucumber would eventually throw away the food and the rock, and would later just stop performing.
In that experiment, the monkeys considered the fairness of two different types of payment, but when Range and her colleagues did a similar study with their trained dogs, testing to see if dogs would become upset if they only got bread when other dogs received sausage, they found that dogs did not make that kind of subtle (细微的) distinction. As long as the dogs got some kind of food payment, even if it wasn’t the most delicious kind, they would play along.
【小题1】 The dogs refused to give their paws when they _____________________.

Never before had I imagined I should have the opportunity to live with so many girls．Would  they 　36　such a single “Hi” from me? I was about to greet my new roommates，　37　they did  not seem to have the same 　38　attention that I had．They just dealt with their own 　39　， sorting out their clothes，and making arrangements for their university life．Thus tranquility（宁静）
became the 　40　atmosphere in the dormitory．
To my surprise，　41　such a situation，I did not feel a sense of 　42　．With time going on，we got to know each other deeper．I was　43　to find that in deep soul we all had great dreams and belonged to the same　44　．
However，not long before the 　45 　was disturbed by my own upset of mind for study pressure．What I was　46　about seemed to have 　47　to do with them and what they were doing and talking about seemed so far away from me．However，one incident changed my 　48　and made me treasure this kind of 　49　better and more confident in our friendship．
One day，when I was leaving the teachers’ office，it was in complete silence and frightening 　50　．At my dormitory gate，I was startled （使惊奇）to find there still 　51 　a little light glimmering in the darkness，so faint but yet so clear．Just under the 　52　of the light，I went to the room without any difficulty．They were in sound sleep，leaving the 　53　light on in the calm world．Tears rolled down my cheeks．
I know 　54　that we all like tranquility，both in environment and in our mind．It is the care that 　55　all the misunderstandings and unpleasantness．

Everybody is happy as his pay rises. Yet pleasure at your own can disappear if you learn that a fellow worker has been given a bigger one. Indeed, if he is known as being lazy, you might even be quite cross. Such behavior is regarded as “all too human”, with the underlying belief that other animals would not be able to have this finely developed sense of sadness. But a study by Sarah Brosnan of Emory University in Atlanta, Georgia, which has just been published in Nature, suggests that it is all too monkey, as well.
The researchers studied the behaviors of some kind of female brown monkeys. They look smart. They are good-natured, co-operative creatures, and they share their food happily. Above all, like female human beings, they tend to pay much closer attention to the value of “goods and services” than males.
Such characteristics make them perfect subjects for Doctor Brosnan’s study. The researchers spent two years teaching their monkeys to exchange tokens (奖券) for food. Normally, the monkeys were happy enough to exchange pieces of rock for pieces of cucumber. However, when two monkeys were placed in separate and connected rooms, so that each other could observe what the other is getting in return for its rock, they became quite different.
In the world of monkeys，grapes are excellent goods (and much preferable to cucumbers). So when one monkey was handed a grape in exchange for her token, the second was not willing to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either shook her own token at the researcher, or refused to accept the cucumber. Indeed, the mere presence of a grape in the other room (without an actual monkey to eat it) was enough to bring about dissatisfaction in a female monkey.
The researches suggest that these monkeys, like humans, are guided by social senses. In the wild, they are co-operative and group-living. Such co-operation is likely to be firm only when each animal feels it is not being cheated. Feelings of anger when unfairly treated, it seems, are not the nature of human beings alone. Refusing a smaller reward completely makes these feelings clear to other animals of the group. However, whether such a sense of fairness developed independently in monkeys and humans, or whether it comes from the common roots that they had 35 million years ago, is, as yet, an unanswered question.
【小题1】According to the passage, which of the following statements is TRUE?