有几道想不通的逻辑题请大家指教并一起探讨

The museum’s night security guard maintains that the
thieves who stole the portrait did not enter the museum at any point at or
above ground level. Therefore, the thieves must have gained access to the
museum from below ground level.

The flawed pattern of reasoning in the argument above is
most similar to that in which one of the following?

(A) The rules stipulate the
participants in the contest be judged on both form and accuracy. The eventual
winner was judged highest in neither category, so there must be a third
criterion that judges were free to invoke.

(B) The store’s competitors
claim that the store in selling off the shirts at those prices, neither made
any profit nor broke even. Consequently, the store’s customers must have been
able to buy shirts there at less than the store’s cost.

(C) If the census is to be
believed, the percentage of men who are married is higher than the percentage
of women who are married. Thus, the census must show a higher number of men
than of women overall.

(D) The product label
establishes that this insecticide is safe for both humans and pet. Therefore,
the insecticide must also be safe for such wild mammals as deer and rabbits.（B）

(E) As had generally been
expected, not all questionnaires were sent in by the official deadline. It
follows that plans must have been made for the processing of questionnaires
received late

我认为的答案是A, 真正的答案是B.我是我怎么也想不通B为什么和题的逻辑相似？

.

Policy Adviser: Freedom of speech is not only a basic human
right; it is also the only rational policy for this government to adopt. When
ideas are openly aired, good idea flourish, silly proposals are easily
recognized as such, and dangerous ideas can be responded to by rational
argument. Nothing is ever gained by forcing citizens to disseminate their
thoughts in secret.

20.   The policy adviser’s method of persuasion, in recommending a
policy of free speech to the government, is best described by which one of the
following?

(A) a
circular justification of the idea of free speech as an idea that flourishes
when free speech is allowed

(B)
advocating respect for basic rights of citizens for its own sake

(C) a
coupling of moral ideals with self-interest

(D) a
warning about the difficulty of suppressing the truth（C）

(E) a
description of an ideal situation that cannot realistically be achieved

22.   The trustees of
the Avonbridge summer drama workshop have decided to offer scholarships to the
top 10 percent of local applicants and the top 10 percent of nonlocal
applicants as judged on the basis of a qualifying audition. They are doing this
to ensure that only the applicants with the most highly evaluated auditions are
offered scholarships to the program.

Which one of the following points out why the trustees’
plan might not be effective in achieving its goal?

(A) The best actors can also
apply for admission to another program and then not enroll in the Avonbridge
program.

(B) Audition materials that
produce good results for one actor may disadvantage another, resulting in
inaccurate assessment.

(C) The top 10 percent of local
and nonlocal applicants might not need scholarships to the Avonbridge program.

(D) Some of the applicants who
are offered scholarships could have less highly evaluated auditions than some
of the applicants who are not offered scholarships.（D）

(E) Dividing applicants into
local and nonlocal groups is unfair because it favors nonlocal applicants.

第一题应该是B

因为题目是由守卫说的话推出结论，而守卫说的话未必是事实

A选项是由事实推出，而B也是也是有竞争者说的话推出的，他说的话未必是事实

there is possibility that nolcal students outnumber the local students, so the resoning favors the local students rather than the nolacal students E mentioned.