81.The program to control the entry of illegal drugs into the country was a failure in 1987. If the program had been successful, the wholesale price of most illegal drugs would not have dropped substantially in 1987.

The argument in the passage would be most seriously weakened if it were true that

(A) in 1987 smugglers of illegal drugs, as a group, had significantly more funds at their disposal than did the country’s customs agents

(B) domestic production of illegal drugs increased substantially in 1987

(C) the author’s statements were made in order to embarrass the officials responsible for the drug-control program

(D) in 1987 illegal drugs entered the country by a different set of routes than they did in 1986 B

(E) the country’s citizens spent substantially more money on illegal drugs in 1987 than they did in 1986.

这题我的思路是：successful=>price increase那么反过来就是price drop=>programm failure

answer B说domestic production increase=>price drop 所以并不是programm failure了，这我也能理解

但是根据D的话 可以得到  routes多了可以更加导致programm failure,这么一来并不是因为price drop导致了programm failure，那么不也是weaken原题了么？

希望大家指教阿~~

 D, routes多了为什么会weaken呢？我不明白？

routes多了，并不能说明流入的毒品的量就多，可能还少了呢。。。光这样并不能对结论进行weaken啊。

B. 国内的产量并不代表国外流入，题目说，如果控制了国外流入的毒品，那么毒品批发价格就会上升。。。所以并不能说明政府控制计划失败了。这个才是weaken啊。