[求助]LAST-5-2-4

4.     A work of architecture, if it is to be both inviting and functional for public use, must be unobtrusive, taking second place to the total environment. Modern architects, plagued by egoism, have violated this precept. They have let their strong personalities take over their work, producing buildings that are not functional for public use.

Which one of the statements below follows logically from the statements in the passage?

(A) Unobtrusive architecture is both inviting and functional.

(B) Modern architects who let their strong personalities take over their work produce buildings that are not unobtrusive.

(C) An architect with a strong personality cannot produce buildings that functional well for the public.

(D) A work of architecture that takes second place to the environment functions well for public use.（B）

(E) A work of architecture cannot simultaneously express its architect’s personality and be functional for public use.

正确答案是（B），也看了以前的帖子，但是对于（B）有些问题还是没搞明白

我的想法：it is to be both inviting and functional for public use——

          must be unobtrusive——

          let their strong personalities take over their work——

原文的逻辑关系也就可以表示为：→   →not

（B）选项的逻辑关系也就是：→not

如果以上我所理解的逻辑关系没有错误的话，顺着（B）的逻辑关系往回推，即：

由→not    not→not 可以得到  →not，

正好得到原文中另一个逻辑条件

但是，如果由原文的逻辑关系推答案（B）时问题出现了：

∵→

∴not→not

又∵→not

∴→not （B）   这样的推理难道成立吗？如果可以这样推的话，那也完全有可能是

not→ 啊

不知道自己什么地方想错了，希望有人可以帮我看看问题到底在哪里啊

you are wrong in the first step. it is not 1 --> 2, instead, it is 2--> 1

the first sentence =>must be unobtrusive, in order to be both inviting and functional.

so, 2 is the necessary condition for 1. => if we get 1, we must have 2 (but if we get 2, we may not necessarily get 1)

if 3 cuases 1, then it must belong to 2.

呀，原来第一步就错了啊，很受打击啊，看来我要好好把这些充分啊、必要啊条件好好复习一下了

谢谢版主的指点，明白了：）