[求助]GWD7-13困惑

Q2:
Guidebook writer:  I have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward.  Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who have worked on hotels built subsequently.

Which of the following, if true, most seriously weakens the guidebook writer’s argument?

A The quality of original carpentry in hotels is generally far superior to the quality of original carpentry in other structures, such as houses and stores.
B Hotels built since 1930 can generally accommodate more guests than those built before 1930.
C The materials available to carpenters working before 1930 were not significantly different in quality from the materials available to carpenters working after 1930.
D The better the quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished.
E The average length of apprenticeship for carpenters has declined significantly since 1930.
   Answer: D

首先说说我的看法，我认为题目是个因果关系，作者认为skill，effort导致carpentry质量好，而正确选项D说质量越好，越不容易塌，换言之，就是因为质量好导致不容易塌，质量好在答案里怎么变成原因了，要是这样的话能说他SUPPORT THE ARGUMENT吗？麻烦斑竹解答

还有一个题，GWD7-31

Studies in restaurants show that the tips left by customers who pay their bill in cash tend to be larger when the bill is presented on a tray that bears a credit-card logo.  Consumer psychologists hypothesize that simply seeing a credit-card logo makes many credit-card holders willing to spend more because it reminds them that their spending power exceeds the cash they have immediately available.

Which of the following, if true, most strongly supports the psychologists’ interpretation of the studies?

A The effect noted in the studies is not limited to patrons who have credit cards.
B Patrons who are under financial pressure from their credit-card obligations tend to tip less when presented with a restaurant bill on a tray with credit-card logo than when the tray has no logo.
C In virtually all of the cases in the studies, the patrons who paid bills in cash did not possess credit cards.
D In general, restaurant patrons who pay their bills in cash leave larger tips than do those who pay by credit card.
E The percentage of restaurant bills paid with given brand of credit card increases when that credit card’s logo is displayed on the tray with which the bill is prepared.
   Answer: B

题目说有credit card的logo，导致给tip多，B项说遇到金融麻烦的人在看到有logo比没logo时给的tip就少，为什么B项能增强结论呢？难道是题目的结论是logo与tip有关，我觉得这不是结论啊，麻烦斑竹达人一并给解决了

第一题：

质量好的不塌，质量不好的早就塌了，作者当然只能看到过去最好的建筑，并拿这个建筑和之后的建筑做比较，即拿着精华和平常的事务做比较，结论可想而至是有问题的。但其实只是其没有也没这个可能看到过去不好的建筑而已，因为他们已经塌了。

第二题文章假设，人们看到信用卡记号就会提醒自己，自己的消费能力大于手边的现金，因而会给更多的tip

问支持

B，已经在经济危机中的人们，看到信用卡记号自然会提醒自己，你已经没什么钱了，还是不要给消费了。

质量好的不塌，质量不好的早就塌了，作者当然只能看到过去最好的建筑，并拿这个建筑和之后的建筑做比较，即拿着精华和平常的事务做比较，结论可想而至是有问题的。但其实只是其没有也没这个可能看到过去不好的建筑而已，因为他们已经塌了。

这个解释好！！，我觉得自己有点死板，就是老抓住这道题的结论因果关系不放，原来是这个意思，看了心情舒畅了