Help OG 208

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

the answer is (E)

I got headache in this question.  Can someone help translate it into Chinese?

What is the meaning of "tissue"?  Are "tooth and bone" tissues?  What is meaning of "tissues not normally found in the organ in which the tumor appears"?  What is difference between "tissue" and "organ"?

I totally got lost.  Thank you very much for your help!!!

Teratomas是普通的癌症形式，在于T是由tooth和bone之类的tissue(组织)组成的，这些组织通常没有在肿瘤出现的器官中被发现。

tissue - 组织；比如人体的神经组织、表皮组织、肿瘤等等，在偶看来，只要是个身体器官(organ)或器官生出来的东西(比如：tumor)都可以被看作是tissue的一个部分。

Thank you very much, STONEREN!!!  Hope I can figure out this time.

请问in that 后的they不会引起歧义吗？他可以修饰teratomas,亦可以指forms，而且我觉得他修饰forms的嫌疑更大。

因为in that 有限定修饰的作用，应该修饰前面短语的中心词，也就是forms吧。

根据句子含义，they 指代主句主语 Teratomas。

如果要指代 forms 的话，用定语从句就可以了，不需要原因状语从句。

收到，明白，谢谢！

选项D不明白：
(D) in that their composition, tissues such as tooth and bone, is

这里的 tissues 为 composition 的同位语，起解释说明作用。也就是说 composition 就是tissues，
即：their compositions = Teratomas' tissues

看起来 D 和 E 表达了同样的意思，但为什么og解释说：The confused syntax of D states that their composition, not the tissues, is found in the organ....

同位语的话有一个要求：tissues包涵的内容范围要大于composition得范围，但是事实上并不是这样的，所以D这个同位语本身就是不对的！

同位结构的形式:
* 名词性同位语: 名词解释名词,如本题
* 内容具体化同位结构:  抽象名词(theory/evidence/belief/principle)+that从句,that从句对抽象名词进行具体化解释(注意与of结构的区别)
* 概括性同位语: 用一个概括性的名词去概括前面的修饰对象:短语/句子,a program/information/an effort/ a practice that…
* 名词重复性同位结构: n,n(重复所修饰的名词)+that定语从句
* 代词代替性同位结构: n,one/ones+that定语从句

你说的“tissues包涵的内容范围要大于composition的范围”，大概属于上面概括性同位语这一类吧。但我还是不明白怎么判断哪个范围更大，继续请教！