求问PREP08 CR里的一道题

葱花kdku

附上原题：

In a study conducted in Pennsylvania, servers in various restaurants wrote “Thank you” on randomly selected bills before presenting the bills to their customers. Tips on these bills were an average of three percentage points higher than tips on bills without the message. Therefore, if servers in Pennsylvania regularly wrote “Thank you” on restaurant bills, 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 Pennsylvania does not vary with how expensive a restaurant is.
E.Virtually all patrons of the Pennsylvania restaurants in the study who were given a bill with “Thank you” written on it left a larger tip than they otherwise would have.

正确答案是B....我觉得是A，B我怎么也推不出是原文的假设，有人能给我解释一下为什么吗？
我觉得A是对的，我的分析：写“thank you”对常客和新顾客都有一样的作用，写thank you给顾客（这里的顾客就分为常客和新顾客）会得到更多的小费，所以常客的消费会增加，新顾客的小费也会增加，所以会增加最终的income,是原文的假设。。。

danyuchn

A選項是加強題的答案，不是假設題的答案。樓主可能要考察一下加強題與假設題答案的差別：雖然態度都是站在跟結論同邊，但是加強的選項若不確定是否為真，結論不會被證偽。而假設題的選項若不能確定100%存在，結論肯定會被weaken。

加強選項就像是一碗牛肉麵裡的蔥花，沒了蔥花這碗麵還是牛肉麵。假設題就像是一碗牛肉麵的牛肉，沒了牛肉還能叫牛肉麵嗎？

將A選項取非後，會變成「非常客不會因為這樣多給小費」
就算今天賺不到非常客的小費，但是餐廳的收入真的會減少嗎？
所以結論沒有被削弱到。

B選項取非後，會變成「如果變成制式天天做，顧客就會把給較多小費的習慣改回來」
這種時候餐廳肯定是賺不到更多的小費了。所以結論就會削弱了。

shanelavigne

danyuchn 发表于 2017-10-18 15:36
A選項是加強題的答案，不是假設題的答案。樓主可能要考察一下加強題與假設題答案的差別：雖然態度都是站在 ...

同意！               

growing0424

danyuchn 发表于 2017-10-18 15:36
A選項是加強題的答案，不是假設題的答案。樓主可能要考察一下加強題與假設題答案的差別：雖然態度都是站在 ...

啊谢谢解释！！！！！！

laughingwind

对A进行取非，说老顾客和新顾客看到thank you给的小费是不一样的，比如说老顾客看到thank you多给2%，新顾客多给5%，新老顾客加一起平均多给3%，很合理啊，没有削弱原文结论。

梦季

Mark一下！