请教各位prep疑惑~~

wendy24

22.

Herbicides allow cereal crops to be grown very efficiently, with virtually no competition from weeds.  In Britain, partridge populations have been steadily decreasing since herbicide use became widespread.  Some environmentalists claim that these birds, which live in and around cereal crop fields, are being poisoned by the herbicides.  However, tests show no more than trace quantities of herbicides in partridges on herbicide-treated land.  Therefore, something other than herbicide use must be responsible for the population decrease.

Which of the following, if true about Britain, most seriously weakens the argument?

(A) The elimination of certain weeds from cereal crop fields has reduced the population of the small insects that live on those weeds and that form a major part of partridge chicks' diet.
(B) Since partridges are valued as game birds, records of their population are more carefully kept than those for many other birds.
(C) Some of the weeds that are eliminated from cereal crop fields by herbicides are much smaller than the crop plants themselves and would have no negative effect on crop yield if they were allowed to grow.
(D) Birds other than partridges that live in or around cereal crop fields have also been suffering population declines.
(E) The toxins contained in herbicides typically used on cereal crops can be readily identified in the tissues of animals that have ingested them.
第一句Herbicides allow cereal crops to be grown very efficiently, with virtually no competition from weeds. 及说明了无竞争答案A的 The elimination of certain weeds from cereal crop fields has reduced the population不是反对前提吗？？？


36 Traveler:  Southern Airways has a far worse safety record than Air Dacentaria over the past few years, in terms of both the frequency of accidents and the severity of accidents.  Therefore, although Air Dacentaria is slightly more expensive, I will choose it over Southern Airways for my flight from Pederton to Dacenta, since it is worth paying extra to have a safer flight.

Which of the following, if true, casts the most serious doubt on the traveler's argument?

(A) Air Dacentaria's flight from Pederton to Dacenta is nonstop, whereas Southern Airways' flight touches down in Gorinda on the way.
(B) Most Southern Airways flights, but not its flight from Pederton to Dacenta, use Sarmouth airport, which because of its mountainous location is one of the world's most dangerous.
(C) For its flights from Pederton to Dacenta, Southern Airways uses a different model of airplane, with a smaller capacity, than the model Air Dacentaria uses for its flights on the same route.
(D) Only in the last few years has the cost of flying from Pederton to Dacenta been more expensive on Air Dacentaria than on Southern Airways.
(E) Although the frequency of accidents is greater on Southern Airways, on both airlines the proportion of flights that have accidents is very small.


B中 大部分的SA班机都用世界上最危险的机场，而P到D没有 那怎么削弱了traveler's argument呢？


18.
The Calex Telecommunications Company is planning to introduce cellular telephone service into isolated coastal areas of Caladia, a move which will require considerable investment.  However, the only significant economic activity in these areas is small-scale coffee farming, and none of the coffee farmers make enough money to afford the monthly service fees that Calex would have to charge to make a profit.  Nevertheless, Calex contends that making the service available to these farmers will be profitable.

Which of the following, if true, provides the strongest support for Calex's contention?

(A) Currently, Caladian coffee farmers are forced to sell their coffee to local buyers at whatever price those buyers choose to pay because the farmers are unable to remain in contact with outside buyers who generally offer higher prices.
(B) In the coastal areas of Caladia where Calex proposes to introduce cellular telephone service, there is currently no fixed-line telephone service because fixed-line companies do not believe that they could recoup their investment.
(C) A cellular telephone company can break even with a considerably smaller number of subscribers than a fixed-line company can, even in areas such as the Caladian coast, where there is no difficult terrain to drive up the costs of installing fixed lines.
(D) Calex bases its monthly fees for cellular telephone service in a given region partly on the cost of installing the necessary equipment to provide the service there.
(E) Calex has for years made a profit on cellular telephone service in Caladia's capital city, which is not far from the coastal region.


这题不太明白答案A和C,D







prep1.
43.
Paint on a new airliner is usually applied in two stages:  first, a coat of primer, and then a top coat.  A new process requires no primer, but instead uses two layers of the same newly developed coating, with each layer of the new coating having the same thickness and weight as a traditional top coat.  Using the new process instead of the old process increases the price of a new aircraft considerably.

Which of the following, if true, most strongly indicates that it is in an airline's long-term economic interest to purchase new airliners painted using the new process rather than the old process?

(A) Although most new airliners are still painted using the old process, aircraft manufacturers now offer a purchaser of any new airliner the option of having it painted using the new process instead.
(B) A layer of primer on an airliner weighs more than a layer of the new coating would by an amount large enough to make a difference to that airliner's load-bearing capacity.
(C) A single layer of the new coating provides the aluminum skin of the airliner with less protection against corrosion than does a layer of primer of the usual thickness.
(D) Unlike the old process, the new process was originally invented for use on spacecraft, which are subject to extremes of temperature to which airliners are never exposed.
(E) Because the new coating has a viscosity similar to that of a traditional top coat, aircraft manufacturers can apply it using the same equipment as is used for a traditional top coat.

C项不明白这句子意思请帮忙分析下~~感激不尽~

j320fish

hi，可以麻烦楼主发我一份prep 07 CR和答案吗？因为论坛里的都是解析版，jyh320[在] yahoo.cn
谢谢了！
解答第22题：A和argument无关：因为文中therefore。。。是要消弱。。。所以答案必须是：herbicide must be responsible for the population decrease,而选项中有关的即C和E，E中内容与文中矛盾。

wendy24

LS意思是22题选C?? 可是我这里答案显示的是A阿 C我觉得是无关比较呢。。。

wildmantomba

建议LZ一题题问 比较有人会解答
还有上面这些题目搜寻一下应该会有很多答案

search in google with the text below
site:  forum.chasedream.com/GMAT_CR  "art of the question you want to ask"

xiaoyu612

可以麻烦楼主发我一份prep 07 CR和答案吗
谢谢了！