og-20-124

forgmat66

Passage 20

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.

请 问 B如 果 不 起 加 强 的 作 用 ， 那 是 不 是 起 削 弱 的 作 用 呢 ？

多 谢

ProteinMonica

这道题我也做错了，我的理解是，是不是说 "Interest in outdoor recreation began to grow" 不一定等同于 "the growth of the suburbs  and increased outdoor recreational activities in the deer’s habitat."

因为interest grow 不一定造成人数的实际增加；此外，即使户外活动人数增加，也不一定代表 deer's habitat 的户外活动人数增加。

所以相比之下A更好些。