26. (31045-!-item-!-188;#058&004365)
The population of Megacity, a sprawling metropolis in Remsland, has grown at a fairly steady rate for over a century. A hundred years ago, poor sanitation in the city caused high mortality rates among the city's inhabitants, and what fueled the population increase was immigration from rural villages. This immigration has continued and even increased. Moreover, in recent decades, city sanitation has improved enormously. Yet the city's population growth has not significantly accelerated.
Which of the following, if true, most helps to explain why the city's population growth rate has not changed?
(A) Mortality rates that were associated with poor sanitation in Megacity a hundred years ago were orders of magnitude higher than are mortality rates associated with vehicular traffic, which is currently a major cause of death in the city.
(B) For several decades, Megacity, as distinct from the countryside, has had a steadily declining birth rate.
(C) Cities smaller than Megacity have also experienced sustained population growth.
(D) The great majority of immigrants to Remsland settle in Megacity, at least initially.
(E) Megacity has long offered better employment prospects than most rural areas.
答案是B。
我的疑问是，A和B一样，也是给出他因来说人口为什么还是没有明显增加。为什么B对，而A错呢？
A.一百年前因为卫生太差而死的人比因为车辆事故而死的人多，在城市中因为车辆事故而死亡目前是死亡的主要原因。
B.几十年来，M市与农村不同，一直出生率不断降低。
已经知道了
A说的是一百年前M城因卫生条件差而导致的死亡率远远高于现在车祸引致的死亡率，而车祸致死现在成为M城的首因。按A的说法，M城人口应该增加才是（现在的死亡率下降了）。
人口增长率没上升，而死亡率可能下降了，还有移民到此的贡献，就应该想人口增长受两方面影响，一个是死亡数量一个是出生数量，既然死亡数量走不通，就应该从出生数量入手
一开始也选了A 现在觉得A无关
A 不管因为什么死，都是死
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