再请教！

tongxun

189. 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
正确选项是C。且不论其它方面的问题，单纯从句子分析，会发现C选项出现：like an expert的情况。他与什么比较？与computers，似乎数量不一；与reason---动作比，又无可比性；与computers reason 比，似乎应该用as an expert does。总之，在以前做本题时没注意，当时觉得挺顺的，但现在分析起来，反而糊涂了！
请大家不吝赐教！

sunny

1、比较的关键在于有没有可比性。而不要太注重属性。电脑和专家在推理方式上是类似，就有可比性。所以computer和expert可以比较。
2、单复数的问题，个人认为此处单数更恰当一些。我们强调的是电脑的共性，即尽管电脑很多（computers），但电脑在推理时方式是一致的，所以用an expert表泛指的同时强调共性是很恰当。试想假如用experts，岂不是变成电脑象很多专家在同时推理，那么每个专家是否一致呢？电脑又如何从如此多的专家那里得出结论呢？这显然歪曲了原意。这里还是从表达的准确性和有效性上来入手，此处显然强调专家的推理方式，至于是哪个专家，多少个专家不是考虑的范围。

zinco

I think:
if there is no other choice such as the sentence-- like experts, computers..., the choice cited by tongxun, though not be the best choice, can also be the choice.

zinco

In a word, as A do,B can do.....A and B must be the things that can be conpared. it is not enough that A and B only are the noun.A and B must be the analog.

tongxun

a expert 是单数，而computers 是复数，单复数可比吗？例如将前面的改写为：
Like a expert， computers。。。。。这样可以吗？种类不同、数字不同！

rocker

If you simplify "computers that can understand English and other human languages, recognize objects, and reason" as "computer" ( that ... is all referred to computer), then it's obvious to use "like a expert"; and also how to use "such as"  can help you identify the correct one.