(2019·武汉调研)Owning a dog is associated with a significantly lower risk of heart disease and death，according to a comprehensive new study published by a team of Swedish researchers on Friday in the journal Scientific Reports.
The scientists followed 3.4 million people over the course of 12 years and found that adults who lived alone and owned dogs were 33 percent less likely to die during the study than adults who lived alone without dogs.In addition，the single adults with dogs were 36 percent less likely to die from heart disease.
“Dog ownership was especially prominent as a protective factor in people living alone，who are a group reported previously to be at higher risk of heart disease and death than those living in a multiperson household，” Mwenya Mubanga，a Ph.D.student at Uppsala University in Uppsala，Sweden，and the lead junior author of the study，said in a statement announcing its findings.The link between dog ownership and lower mortality(死亡率) was less pronounced in adults who lived either with family members or partners，but still present, according to the study.“Perhaps a dog may stand in as an important family member in the single household，”Mubanga added.“Another interesting finding was that owners of dogs which were intended originally for hunting were most protected.”
The study，which is the largest to date on the health relations of owning a dog，suggested that one of the reasons why dog owners may have a lower risk of mortality and heart disease was that dog owners walked more.“These kinds of epidemiological(流行病学的)studies look for associations in large populations but do not provide answers to whether and how dogs could protect their owners from heart disease，”Tove Fall，a senior author of the study and a professor at Uppsala University，said in a statement.
“We know that dog owners in general have a higher level of physical activity，which could be one explanation for the observed results.”Fall added.“Other explanations include increased wellbeing and social contacts or effects of the dog on the bacterial microbiome(微生物菌群) in the owner.”Fall added that because all participants of the study were Swedish，the results most closely apply to dog owners in Sweden or other“European populations with similar culture regarding dog ownership”．
【语篇解读】 本文是生活类说明文。作者首先介绍了一项研究结果：养狗可以降低患心脏病及死亡的风险，接下来分析了可能产生这种结果的原因。
1．Why did the researchers do the study related to 3.4 million people's health and the dogs?
A．To help Europeans.
B．To find their association.
C．To protect unhealthy adults.
D．To reduce the risk of heart disease.
B [细节理解题。文章第一段提出了一项研究成果：养狗可以降低患心脏病和死亡的风险。第二段讲的是科学家们在十二年间研究了三百四十万人，他们发现养狗的独居成年人比不养狗的独居成年人的死亡率要低33%，也就是说，做这项研究是为了发现两者之间的关系，所以选B。]
2．What does the underlined word“prominent”probably mean in Para.3?
A．Universal. B．Confusing.
C．Appealing. D．Important.
D [词义猜测题。根据语境可知，独居的人跟那些生活在多人口家庭里的人相比，他们患心脏病以及死亡的风险更高。所以，作为一种保护因素，养狗对独居的人来说尤其“重要”，故选D项。]
3．What's the main idea of the text?
A．Adults living with dogs are less likely to die.
B．Swedish people are very fond of pets.
C．Keeping a dog is a popular and healthy hobby.
D．Owning dogs reduces the risk of heart disease.
D [主旨大意题。文章第一段就提出了研究结果：养狗可以降低患心脏病及死亡的风险，之后分析了可能产生这种结果的原因，故选D项。]
4．What's the writer's attitude towards owning a dog?
A．Positive. B．Negative.
C．Objective. D．Contradictory.
C [作者态度题。作者在介绍了研究结果之后，接着用研究报告及研究人员的言论分析了可能导致这种结果的原因，其中并没有表明作者自己的态度，只是在用事实说话，不带有个人意见，因此是客观的，所以选C。]
