难道只有我最笨，没人问过的OG208

208. Teratomas are unusual forms of cancer because they are composed of tissues such as tooth and bone not normally found in the organ in which the tumor appears.

(A)  because they are composed of tissues such as tooth and bone

(B)  because they are composed of tissues like tooth and bone that are

(C)  because they are composed of tissues, like tooth and bone, tissues

(D)  in that their composition, tissues such as tooth and bone, is

(E)   in that they are composed of tissues such as tooth and bone, tissues(正确答案)

Only E, the best choice, clearly states that teratomas consist of tissues such as tooth and bone, and that such tissues are not normally found in the organ with the teratoma. Clear statement of this fact requires the repetition of tissues to establish the appositive--tissues normally found.... Without such repetition, A and B imprecisely state that the tooth and bone, as opposed to the tissues, are not normally found in the affected organ. Choices B and C alter the meaning with the use of like', that is, they suggest that the tissues are not tooth and bone, but only like them. The confused syntax of D states that their composition, not the tissues, is found in the organ....

我的疑问是：D选项为什么不对，看了黄色背景部分的OG解释，还是不理解。D选项中，their composition不就是the tissues吗？

我试着把D、E两个选项翻译一下，大家帮我看看，问题出在哪里？

D：因为他们的成分——一些组织如牙齿和骨头，不常在肿瘤生成的器官中被发现。

E：因为他们由一些组织组成，而这些组织不常在肿瘤生成的器官中被发现。

这两个的意思有什么差别呢？核心意义不都是要反映1、Teratomas(畸形瘤)由一些组织组成；2、这些组织不常在肿瘤生成的器官中被发现。

难道和同位语的修饰作用有关？在我的理解中，同位语和它修饰的成分应该是等价的呀？尤其是“名词，名词”形式的同位语，我怎么记得两者是可以互换的呢？

盼您指点！谢谢！

按照你的解释：COMPOSITION=THE TISSUES ， 逻辑意思显然不对。

D means composition is not found in organ.....,no matter what the composition is.

But the sentence originally means that tissues such as tooth and bone are not found in the organ .......

If they were not composed of tooth and bone,the composition would be  found in organ.......

Not composition but tooth and bone are  unusual.

So ,D is not right.

谢谢realmay！好像有点明白了。

不好意思，我再请教一下。

我也不记得什么时候树立了这么一个概念：同位语和它修饰的成分可以互换。是错的啦？

同位语是限定性修饰是吗？也就是说，D选项暗示了还有不是诸如牙齿和骨头这样组织的成份(composition)存在？