大全　　test 6 16 17 20

A researcher discovered that people who have
low levels of immune-system activity tend to score much lower on tests of
mental health than do people with normal or high immune-system activity. The
researcher concluded from this experiment that the immune system protects
against mental illness as well as against physical disease.

16.   The
researcher’s conclusion depends on which of the following assumptions?

(A) High
immune-system activity protects against mental illness better than normal
immune-system activity does.

(B) Mental
illness is similar to physical disease in its effects on body system.

(C) People with
high immune-system activity cannot develop mental illness.

(D) Mental
illness does not cause people’s immune-system activity to decrease.（D）

(E)
Psychological treatment of mental illness is not as effective as is medical
treatment.

17.   The
researcher’s conclusion would be most seriously weakened if it were true that

(A) there was a
one-year delay between the completion of a pilot study for the experiment and
the initiation of the experiment itself

(B) people’s
levels of immune-system activity are not affected by their use of medications

(C) a few
people with high immune-system activity had scores on the test of mental health
that were similar to the scores of people who had normal immune-system activity

(D) people who
have low immune-system activity tend to contract more viral infections than do
people with normal or high immune-system activity（E）

(E) high levels
of stress first cause mental illness and then cause decreased immune-system
activity in normal individuals

20.   Seven
countries signed a treaty binding each of them to perform specified actions on
a certain fixed date, with the actions of each conditional on simultaneous
action taken by the other countries. Each country was also to notify the six
other countries when it had completed its action.

The simultaneous-action provision of the
treaty leaves open the possibility that

(A) the
compliance date was subject to postponement, according to the terms of the
treaty

(B) one of the
countries might not be required to make any changes or take any steps in order
to comply with the treaty, whereas all the other countries are so required

(C) each
country might have a well-founded excuse, based on the provision, for its own
lack of compliance

(D) the treaty
specified that the signal for one of the countries to initiate action was
notification by the other countries that they had completed action（C）

(E) there was
ambiguity with respect to the date after which all actions contemplated in the
treaty are to be complete

答案分别是　　D E C　　但不知为何？？

16、17题：典型的求同法求解。狒狒举的例子：在一个山洞里发现了动物和人的骨头，A说动物把人吃掉了，A的前提是人没有把动物吃掉，B可以用来削弱A的说法是“确信就是人把动物吃掉了”。所以说当两个有关联的事物同时出现时，假设和削弱的方法就是把原文中的逻辑关系反向。

对应于16题，题干说是因为 immune-system 影响了Mental illness ，假设类题目取非就是 Mental illness does not cause people’s immune-system activity to decrease。17题同理解释。

20题：7个国家在一个固定的时间里完成相应的事情，一方以另一方simultaneous action 为条件，同时还需要互相通知完成的状况，这不是“互相扯皮不干事”的最好条件吗？其他的几个选项都是超出题干可以预测范围了。

each conditional on simultaneous action taken by the other countries，设想，在 simultaneous action 之前总有个谁先打第一枪的问题吧？但是题中又讲了conditional on simultaneous action，也就是每一个国家都有理由在所有国家同时在干的时候才行动的。这不就出问题了不?

呵呵，个人理解就是这样的，希望有所帮助，请各位NN指正。

在做题的过程中发现了LS说的那个逻辑关系反向的问题，　　一类题　

谢谢LS的解释啊