OG11SC,100题，疑问，关于“--”的用法

100．Proponents
of artificial intelligence say they will be able to make computers that can
understand English and other human languages，recognize
objects，and reason as an expert
does--computers that will be used to diagnose equipment breakdowns, deciding
whether to authorize a loan，or
other purposes such as these．

(A)  as an expert does-computers that will be used
to diagnose equipment breakdowns，deciding
whether to authorize a loan，or other purposes
such as these

(B)  as an expert does，which may be used for purposes such as diagnosing
equipment breakdowns or deciding whether to authorize a loan

(C)  like an expert-computers that will be used for
such purposes as diagnosing equipment breakdowns or deciding whether to
authorize a loan

(D)  like an expert，the use of which would be for purposes like the diagnosis
of equipment breakdowns or the decision whether or not a loan should be
authorized

(E)  like an expert，to be used to diagnose equipment breakdowns，deciding whether to authorize
a loan or not，or the like

Parallelism +Rhetorical construction

The sentence presents three
functions of intelligent computers，but
these functions(to diagnose…，deciding… or other purposes) are not
written in parallel ways．Moreover,
the final function is vague．Turning this
final function into an introductory statement and using parallel forms for the
two dements diagnosing and deciding creates a stronger sentence．Either the clause，as an expert does, or the
prepositional phrase, like an expert, is correct and idiomatic in this sentence．
    

A  The series to diagnose…，deciding…，or
other purposes should be expressed in parallel ways．

B  which has no clear referent．

C  Correct．Moving
for such purposes as to an introductory position strengthens the sentence；diagnosing and deciding are
parallel．

D To diagnose and deciding are
not parallel；the use of which would be for
purposes like is wordy and awkward；which
has no clear referent．

E  To be used, deciding, and or the like are not
parallel．

The correct answer is C．

各
位前辈，我不太明白的就是为什么这里还能再出现一个名词，作为类似的伴随状语或者同位语，是因为“-”的关系吗？这类题目我都不是太懂，如果真要我硬理解这样的结构
的话，我会理解成，I am A(名词)， B(另一样东西，但是等同)。或者说是They can make(制造)
computers-（which is）computers。

还有就是为什么用了which反而是no clear referent了。

张道真上说“－”可以：总结前面列举的若干东西。我想这里的用法就是这样的。

另外这个题目用排除法可以比较方便的获得正解。

ETS对which的要求一向是指代要明确吧，做定语的时候最好紧跟前面的主体词。这个句子which如果引导computer的定语从句，隔离的未免也太远了点。

个人意见仅供参考。。。

 我来解释下吧 我用我们老师的方法给你解释下 XDF的

 which有两种用法 1.n,which 有逗号有which　前面还得是名词　

　　　　　　　　2. n+介词+which+svo   它一般是指代前面名词的 不指带整句话

as 一种它表连词 后跟一句话 表对比 跟不完整句子

  一种是介词 跟N