扫描二维码，直接登录
题库 / Prep2007E1-CR-26
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?
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.
For several decades, Megacity, as distinct from the countryside, has had a steadily declining birth rate.
Cities smaller than Megacity have also experienced sustained population growth.
The great majority of immigrants to Remsland settle in Megacity, at least initially.
Megacity has long offered better employment prospects than most rural areas.
类比M城
以前：卫生不好，移民多，导致人口激增
现在：卫生好了，移民也多，人口增长却不快
解释，增强，即找以前和现在的不同点
A、以前卫生不好导致的死亡率比现在交通事故导致的还多，反了，如果它是真的，那以前人口不应该激增，现在人口的增长速度也应该比以前快
（小声bb：老长了，老ex了，老tricky）
B、M的出生率下降，引入他因，可以解释人口增长不快，COORECT
C、比M小的城市人口增长，与M城、M的以前现在无关
D、R的移民都集中在M，移民多，反了，且重复原文，没办法解释人口增长不快
E、M的就业好，也反了……
登录 或 注册 后可以参加讨论