OG-20-124

phyroc

Although genetic mutations in bacteria and viruses

can lead to epidemics, some epidemics are caused by

bacteria and viruses that have undergone no significant

genetic change. In analyzing the latter, scientists have

(5) discovered the importance of social and ecological fac-

tors to epidemics. Poliomyelitis, for example, emerged

as an epidemic in the United States in the twentieth

century; by then, modern sanitation was able to delay

exposure to polio until adolescence or adulthood, at

(10) which time polio infection produced paralysis. Previ-

ously, infection had occurred during infancy, when it

typically provided lifelong immunity without paralysis.

Thus, the hygiene that helped prevent typhoid epidemics

indirectly fostered a paralytic polio epidemic. Another

(15) example is Lyme disease, which is caused by bacteria

that are transmitted by deer ticks. It occurred only spo-

radically during the late nineteenth century but has

recently become prevalent in parts of the United States,

largely due to an increase in the deer population that

(20) occurred simultaneously with the growth of the suburbs

and increased outdoor recreational activities in the

deer’s habitat. Similarly, an outbreak of dengue hemor-

rhagic fever became an epidemic in Asia in the 1950’s

because of ecological changes that caused Aedes aegypti,

(25) the mosquito that transmits the dengue virus, to proliferate

The stage is now set in the United States for a

dengue epidemic because of the inadvertent introduction

and wide dissemination of another mosquito, Aedes

albopictus.

124. Which of the following, if true, would most strengthen the author’s assertion about the cause of the Lyme disease outbreak in the United States?

(A)   The deer population was smaller in the late nineteenth century than in the mid-twentieth century.

(B)   Interest in outdoor recreation began to grow in the late nineteenth century.

(C)   In recent years the suburbs have stopped growing.

(D)  Outdoor recreation enthusiasts routinely take measures to protect themselves against Lyme disease.

(E)   Scientists have not yet developed a vaccine that can prevent Lyme disease.

我知道B,C,D,E不对，可我觉得A也不怎么对。

文中如果说Lyme disease发生在mid-twentieth century，那肯定A是对的。

可我看完全文，并没有讲Lyme Disease发生在什么时候，就是说Lyme Disease有可能是发生在1980s或者1990s，那跟50年代鹿的数量没什么关系啊，因为即使鹿的数量在1950s比19世纪多，到了1980s或1990s也可能减少了，这怎么能支持作者的assertion呢。

[此贴子已经被作者于2007-9-20 17:34:57编辑过]

nuj_am

楼主不要随意假设,文中并未讲写文章的时候是1980s或1990s,做GMAT要保持白痴原则

lukeleng

if true

The deer population was smaller in the late nineteenth century than in the mid-twentieth century.

[此贴子已经被作者于2007-9-21 7:31:47编辑过]

phyroc

谢谢，不过还是有点疑惑...

phyroc

我明白If Ture的意思，白痴原则我也赞同，可是我觉得这句话明显有漏洞