单选题 Noting that the number of crimes committed in a certain city had decreased in 1982 by 5.2 percent in comparison with 1981, the police chief of the city said, "We see here the result of the innovative police program put into effect in the city at the beginning of 1982."
Which of the following, if true, most seriously weakens the conclusion drawn by the police chief?

A、 Several cities that have recently increased spending for police programs experienced no decrease in crime in 1982, as compared with 198l.
B、 The number of crimes committed in the city is estimated, by the same method each year, from the number of crimes reported.
C、 The number of crimes committed in the suburban areas surrounding the city rose by about 5 percent in 1982 over the figure for 1981 and were nearly equal in number to those in the city in 1982.
D、 The number of crimes committed in the city in 1982 was 10 percent higher than the number committed in 1972.
E、 (E) The size of the age group most likely to commit crimes decreased considerably in the city in 1982, as against 1981, because of a declining birth rate.

【正确答案】 E

【答案解析】[解析] 本题推理为：由一个事实“犯罪率下降52%”，得出一个解释性的结论“革新警察计划有效”，属于典型的“B，A”类型，反对的思路一般多用“除了A以外还有其他原因导致B”。如果最易犯罪的年龄组的人数有所减少，正如(E)所说，那么就从另外一个角度解释了B，所以对上面推理起到了反对作用，所以(E)正确。(A)探讨的是其他城市，与我们讨论的某城市无关；(B)说的是共同点，起到了支持的作用；(C)中的“suburban areas”实际上包括在city里面，并且如(C)所言，对段落推理起到的是支持作用。(D)是无关比较，必然不对。