feifei-6 谁是充分条件，谁是必要条件？？？

Questions 5-6

Sales manager: Last year the total number of meals sold in our company restaurants was much higher than it was the year before. Obviously consumers find our meals desirable.

Accountant: If you look at individual restaurants, however, you find that the number of meals sold actually decreased substantially at every one of our restaurants that was in operation both last year and the year before. The desirability of our meals to consumers has clearly decreased, given that this group of restaurants---the only ones for which we have sales figures that permit a comparison between last year and the year before---demonstrates a trend toward fewer sales.

A.        The company’s restaurants last year dropped from their menus most of the new dishes that had been introduced the year before.

B.        Prior to last year there was an overall downward trend in the company’s sales.

C.        Those of the company’s restaurants that did increase their sales last year did not offer large discounts on prices to attract customers.

D.       Sales of the company’s most expensive meal contributed little to the overall two-year sales increase.

E.        Most of the company’s restaurants that were in operation throughout both last year and the year before are located in areas where residents experienced a severe overall decline in income last year.

我知道是用他因，但是我觉得答案的解释我不理解

嗯，看得我晕了。。。一会儿大，一会儿小。呵呵。

你说是原因解释事实，但我觉得这个原因是结论。因为事实，所以推出这个结论。用他因削弱，就是再找出另外的支持有别的原因的事实，来削弱结论。。。

兄弟认为呢？

按照时间来说，谁是因谁是果？  咱们按照时间来说，先发生的是因，后发生的是果

先不喜欢然后sales decrease

这好像就是b--a型的因果

顺着我的理解来

不喜欢就是因

找他因，然后就是经济衰退

果  为 sales decrease 这里的果也就是 事实，前提premise

然后方法是“他因解释前提”

讨论~~~

但A怎么解释？餐馆将菜单撤走，也可能是meals销售下降的原因啊。这不是又一个他因了吗？