prep 2-7,15

7.    (24401-!-item-!-188;#058&001291)

United Lumber will use trees from its forests for two products.  The tree trunks will be used for lumber and the branches converted into wood chips to make fiberboard.  The cost of this conversion would be the same whether done at the logging site, where the trees are debranched, or at United's factory.  However, wood chips occupy less than half the volume of the branches from which they are made.

The information given, if accurate, most strongly supports which of the following?

(A) Converting the branches into wood chips at the logging site would require transporting a fully assembled wood-chipping machine to and from the site.

(B) It would be more economical to debranch the trees at the factory where the fiberboard is manufactured.

(C) The debranching of trees and the conversion of the branches into chips are the only stages in the processing of branches that it would be in United's economic advantage to perform at the logging site.

(D) Transportation costs from the logging site to the factory that are determined by volume of cargo would be lower if the conversion into chips is done at the logging site rather than at the factory.

(E) In the wood-processing industry, branches are used only for the production of wood chips for fiberboard.

我用排除法做出来选d，但不知道为什么。。。

Some airlines allegedly reduce fares on certain routes to a level at which they lose money, in order to drive competitors off those routes.  However, this method of eliminating competition cannot be profitable in the long run.  Once an airline successfully implements this method, any attempt to recoup the earlier losses by charging high fares on that route for an extended period would only provide competitors with a better opportunity to undercut the airline's fares.

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

(A) In some countries it is not illegal for a company to drive away competitors by selling a product below cost.

(B) Airline executives generally believe that a company that once underpriced its fares to drive away competitors is very likely to do so again if new competitors emerge.

(C) As part of promotions designed to attract new customers, airlines sometimes reduce their ticket prices to below an economically sustainable level.

(D) On deciding to stop serving particular routes, most airlines shift resources to other routes rather than reduce the size of their operations.

(E) When airlines dramatically reduce their fares on a particular route, the total number of air passengers on that route increases greatly.

why is b?thanks~~