网上找到的一个解释，感觉比较合理。归根到底是一个平行和歧义的问题。 虽然 “are not...but are” 和 “are not...but” 都可以构成平行，但是由于 But 可以做介词 意思为“除去...”，所以用在这里会产生歧义。如果用 but are 那么 but 就肯定是个连词了，从而消除歧义。favored because they can enhance the reproduction or survival, but simply by-products of ... 这个可以理解为因为他们可以增强再生和生存能力，但不会增强...的副产品。但是作者实际的意思是让But后面和not那一部分平行。
Your first thought here probably was - and should be - parallelism. However, you're right that 'are not ... but are' and 'are not ... but' would both be legitimately parallel constructions in this context. So, the reasoning goes, we should take the one with one fewer word. Right?
Here's the problem: In the context of this longer, more complicated sentence, the 'but' (without 'are' after it) is, unfortunately, ambiguous. Consider this sentence: Jimmy was not the typical class president, loved by most of the students, but also hated by a fair number as well; rather, he was loved by all the students. The most probable reading here is that all of the words 'loved by most of the students, but also hated by a fair number as well' are a description of 'the typical class president.'
If you look at choice C, it can be read this way; one could (probably should, even) take ALL the words '...favored because they enhance reproduction or survival, but simply random byproducts...' as an elaboration on the phrase 'products of natural selection'. It's harder to see than in the example of Jimmy, above, for two reasons: (1) Because of the way the original sentence is written, you're biased toward reading the sentence the way it's 'supposed' to be written. (In the example with Jimmy, there's no prompt sentence, so you're free to read it as you like.) (2) It's longer.
复习到这里，觉得很同意baby姐的思路。能不能省略and后面的主语，和and前面有逗号没有关系，这又是一个grammar invented by Chinese;
还是要看整个句子怎样说更clear without ambiguity.
1. Intar has moved away from the Spanish classics and now draws on the works of contemporary
Hispanic authors. 这个句子省略主语不用说，清晰明了，谁都能懂
2. Intar has moved away from the Spanish classics, and now it draws on the works of
contemporary Hispanic authors. 这个句子逗号前后连时态都不一样，如果不补出主语，是有点不够清晰的，所以补出了it。
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2011-11-30 16:55:10
发表于 2012-1-30 05:36:34
