8.19 求教3道PERT逻辑:( 今天作了15道PERT逻辑 用了快1个小时 结果错了7个 我要疯了

secretnancy

今天错了7个，4个想明白了，剩下3个死也不明白
谢谢好心人帮个忙吧

21. (28551-!-item-!-188;#058&003690)
Traces of cultivated emmer wheat have been found among the earliest agricultural remains of many archaeological sites in Europe and Asia.  The only place where the wild form of emmer wheat has been found growing is a relatively narrow strip of southwest Asia.  Since the oldest remains of cultivated emmer wheat yet found are from village sites in the same narrow strip, it is clear that emmer wheat was first domesticated somewhere in that strip.
Which of the following, if true, most strengthens the argument?
(A) The present-day distribution of another wild wheat, einkorn, which was also domesticated early in the development of agriculture, covers a much larger area of southwest Asia.
(B) Modern experiments show that wild emmer wheat can easily be domesticated so as to yield nearly as well as traditionally domestic strains.
(C) At the time when emmer wheat was first cultivated, it was the most nutritious of all the varieties of grain that were then cultivated.
(D) In the region containing the strip where wild emmer wheat has been found, climatic conditions have changed very little since before the development of agriculture.
(E) It is very difficult, without genetic testing, to differentiate the wild form of emmer wheat from a closely related wild wheat that also grows in southwest Asia.


24. (29155-!-item-!-188;#058&003857)
Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  erhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?
(A) When a prey insect is moved directly toward a beetle that has been chasing it, the beetle immediately turns and runs away without its usual intermittent stopping.
(B) In pursuing a moving insect, the beetles usually respond immediately to changes in the insect's direction, and pause equally frequently whether the chase is up or down an incline.
(C) The beetles maintain a fixed time interval between pauses, although when an insect that had been stationary begins to flee, the beetle increases its speed after its next pause.
我认为是beetles本身速度快，所以视觉需要缓解，和昆虫的运动静止没有关系。所以我没选C@@

(D) If, when a beetle pauses, it has not gained on the insect it is pursuing, the beetle generally ends its pursuit.
(E) When an obstacle is suddenly introduced just in front of running beetles, the beetles sometimes stop immediately, but they never respond by running around the barrier.

34. (31982-!-item-!-188;#058&005681)
For several years, per capita expenditure on prescription drugs in Voronia rose by fifteen percent or more annually.  In order to curb these dramatic increases, the ministry of health prohibited drug manufacturers from raising any of their products' prices.  Even though use of prescription drugs did not expand after this price freeze, per capita expenditure for prescription drugs continued to increase by a substantial percentage each year.
Which of the following, if true, most helps to explain why the ministry's action did not achieve its goal?
(A) After price increases were prohibited, drug manufacturers concentrated on producing new medications to replace existing products.
(B) The population of Voronia rose steadily throughout the period.
(C) Improvements in manufacturing processes enabled drug manufacturers to maintain high profit levels on drugs despite the price freeze.
(D) In addition to imposing a price freeze, the government encouraged doctors to prescribe generic versions of common drugs instead of the more expensive brand-name versions.
(E) After price increases were prohibited, some foreign manufacturers of expensive drugs ceased marketing them in Voronia.

alpaca

比楼主的进度慢一点……
第一个

1.本题的前提是欧亚都发现了很多A物种，但是只有在亚洲某地才有野生的A物种，且最早耕种A的以及叶在此处被发现，结论是A最早在此被驯化。这里有一个gap，因为在这个地方发现驯化以前和驯化以后的A就说A在这里被驯化。因此应该找一个因素衔接驯化前A顺利变成驯化后的A，且这个因素应该与此处地点或其特点相关。
2.注意，A发生了变化，唯一没有变的是地点因素，因此考虑时应该考虑地点的相关因素
我觉得我什么都没说明白……==

第二个
我觉得问题在加速飞行和固定的休息时间。每次停顿之间的间隔相同说明不是突发因素也就是忽然看不到东西引起的，而是累了。如果失明怎么会加速飞行呢？应该是休息完了又有了充沛的精力吧~~

第三个还莫有看到……

loverwy

先声明一下，上述三个题，开始做的时候，我错了两个，只对了最后一个。

#1：我自己开始选B
（1）    前提：CE在欧洲/亚洲的很多地方发现
              WE仅在东南亚某狭窄地带发现
              最早的CE在同一狭窄地带附近发现
（2）    结论：E最早在该狭窄地带被C的（即最早的CE来自于当地的WE，而不是从其他地方的WE来的）。
（3）    具体性：EMMER
（4）    特殊性：最早CE的地点

A: another wild wheat, einkorn （无关）
B: can easily be domesticated （削弱：这样最早的CE就有可能是从其他地方的WE带来过的，且谈及yield无关）
C: the most nutritious （无关）
D: differentiate（无关）

#2：
要求支持一种原因同时削弱另外另一种原因

（1）    结论：TB在追逐猎物过程中要停下来休息
（2）    原因可能有两种：
           X:体力不支，需要经常停下来休息以保持速度
           Y: 不能处理迅速变化的视觉信息、短暂失明，需要停下来思考

A: the beetle immediately turns and runs away without its usual intermittent stopping. （与前提相违背）

B:In pursuing a moving insect, the beetles usually respond immediately to changes in the insect's direction（削弱Y）, and pause equally frequently whether the chase is up or down an incline（削弱X，因为如果是支持X，则当猎物上、下坡的时候更费力，需要停顿的次数更频繁，但现在停顿频率相同，说明不是体力不支）.

C: The beetles maintain a fixed time interval between pauses, although when an insect that had been stationary begins to flee（削弱Y）, the beetle increases its speed after its next pause（支持X）.

#3:

（1）    手段：禁止药商提价
（2）    目的：降低处方药费用
（3）    结果：处方药使用量没下降，但人均处方药支出却大幅上升
（4）    原因？

A:（新药上市时可以直接定个高价）