Press Secretary:  Our critics claim that the President’s recent highway project cancellations demonstrate a vindictive desire to punish legislative districts controlled by opposition parties.  They offer as evidence the fact that 90 percent of the projects canceled were in such districts.  But all of the canceled projects had been identified as wasteful in a report written by respected nonpartisan auditors.  So the President’s choice was clearly motivated by sound budgetary policy, not partisan politics.

Which of the following is an assumption on which the press secretary’s argument depends?

1. Canceling highway projects was not the only way for the President to punish legislative districts controlled by opposition parties.
2. The scheduled highway projects identified as wasteful in the report were not mostly projects in districts controlled by the President’s party.
3. The number of projects canceled was a significant proportion of all the highway projects that were to be undertaken by the government in the near future.
4. The highway projects canceled in districts controlled by the President’s party were not generally more expensive than the projects canceled in districts controlled by opposition parties.
5. Reports by nonpartisan auditors are not generally regarded by the opposition parties as a source of objective assessments of government projects.

答案是B 我选的D 请教我谢谢！

是否expensive与是否wasteful无关，所以D错

为了证明反对党的选区大部分都是不需建高速公路的，总统的决定不是出于党派政治，需选B

我的理解，仅供参考：

Conclusion :Not waste -----> Not cancelled   (因果关系）

Premise 1:  High way project   1.  Cancelled

                                                2.  in opposite district

Premise 2: Press Secretary:    Waste ---------> cancelled

Ansumption：High way project is wastful and the project is in opposite district.  

Thus the secretary identified High way project cancellation is beacause of wastful , not other reason.  the project is in opposite district is just coincidence.

P: C说(因为)D区90%的项目都被否决了.(所以)总统最近对反对党控制的D区H项目的否决是出于政治报复,[因为否决多,所以不公正,所以是政治报复]

P:但是,(因为)否决的项目都经过无党派的审计认定是浪费的,(所以)总统不是出于政治报复.[因为审计说不行,所以否决,所以不是政治报复]

B取非: 类似H被认定浪费的项目在总统党控制的选区经常出现. [审计说不行,没被否决,从而不能推出"所以不是政治报复",原文论证不成立了,所以是assumption.

注)是阅读习惯,[]是翻译成自己的语言

在这里非常同意wondey的分析。我觉得assumption的意思说明原文的论据还不足以推出结论，需要额外的证据。例如原文 a--b,但要是b的观点成立，还必须要c的补充。这样c 就是要选的答案了。

在本题目中，   原来的逻辑关系是说，被否决的项目大多数是wasteful的，因此总统的决定并没有带有政治报复性。要使该结论成立，则必须保证这些wasteful的项目是在反对党控制的地区。如一下关系：

被否决的项目大多数是wasteful+这些wasteful的项目是在反对党控制的地区=---统的决定并没有带有政治报复性.

所以选择B.其余的其实都可以根据是否相关性排除。