Prep VCR 14019 求解答。。。

man855112

Prep2012-Pack1-CR-054 VCR14019 Hard
　　In a study conducted in Canada, servers in various restaurants wrote “Thank you" on randomly selected bills before presenting the bills to their customers. lips on these bills were an average of three percentage points higher than tips on bills without the message. Therefore, if servers in Canada regularly wrote “Thank you” on restaurant their average income from tips would be significantly higher than it otherwise would have been.
　　Which of the following is an assumption on which the argument relies?
　　A. The “Thank you" messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.
　　B. Regularly seeing “Thank you" written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.
　　C. The written “Thank you" reminds restaurant patrons that tips constitute a significant part of the income of many food servers.
　　D. The rate at which people tip food servers in Canada does not vary with how expensive a restaurant is.
　　E. Virtually all patrons of the Canadian restaurants in the study who were given a bill with “Thank you” written on it left a larger tip than they otherwise would have.答案选择B可以理解，不过A错在什么地方，始终看不出来，望高手解答啊，多谢！

zxc1118zxc

首先，Argument中没有提及Regular Patron或者Occasional Patron，所以A选项没有意义。

另外，做Assumption题一个复杂但是保险的方法就是：否定选项然后带回原文，看否定以后Argument是否依然成立。如果依然可以成立，则不是Assumption，如果不再成立则为Assumption
(B) 如果顾客经常看到"thank you"就不会多给出3%的话，那么当然小费收入不会提高；所以选项正确
(A) 就算“Thank you" 对于Regular Patron和Occasional Patron的效果不一样，消费的收入依然可能增多；比如："Thank you"对于Occasional Patron增加2%, Regular Patron增加4%，如果两种Patron各50%，那么最后的效果依然是增加3%。所以这个选项不是Assumption

希望对你有帮助

man855112

多谢多谢！理解了你第二点的意思，
关于第一点，regular patron 相当于regular thanks? 不可以么？
如果是考试中，选项出现了新词，但是可以和文中的词对应，或者接近的概念，这算不算出现新概念？
多谢！