求助GWD-6-Q31

minigreen

220. (GWD-6-Q31)
The fact of some fraternal twins resembling each other greatly and others looking quite dissimilar highlights an interesting and often overlooked feature of fraternal-twin pairs, namely they vary considerably on a spectrum of genetic relatedness.
A.    The fact of some fraternal twins resembling each other greatly and others looking quite dissimilar highlights an interesting and often overlooked feature of fraternal-twin pairs, namely they vary considerably
B.    That some fraternal twins resemble each other greatly while others look quite dissimilar highlights an interesting and often overlooked feature of fraternal-twin pairs, namely that they vary considerably
C.    With some fraternal twins resembling each other greatly and others looking quite dissimilar, it highlights an interesting and often overlooked feature of fraternal-twin pairs, namely considerable variation
D.    With some fraternal twins resembling each other greatly and others looking quite dissimilar, it is a fact that highlights an interesting and often overlooked feature of fraternal-twin pairs, namely a considerable variation        
E.    Because some fraternal twins resemble each other greatly and others look quite dissimilar, this fact highlights an interesting and often overlooked feature of fraternal-twin pairs, namely they vary considerably

答案是B，想问问D为什么不对

prep语法笔记里面对D选项的解释是：
   
It指代正确，因为是结构it is a fact that结构的一部分，强调句；a fact无所指；with独立主格的逻辑主语错误；namely无补充说明对象。

a fact无所指是什么意思？
with独立主格的逻辑主语错误是什么意思呢？独立主格结构不是自带逻辑主语吗？

imddung

个人愚见：
1、a fact无所指是什么意思？
答： fact是一个名词，必须也指代一个名词或者名词性的短语，但是with引导的独立主格不是名词短语，所以a fact无所指代。倘若将With换成That，那么a fact就可以指代前面的主语从句了。
2、with独立主格的逻辑主语错误是什么意思呢？独立主格结构不是自带逻辑主语吗？
答：句子的主语是it，而it指代a fact。而with独立主格这一整句话就是fact，

所以逻辑主语和主句主语不一致。
      你说独立主格自带逻辑主语是对的，要不它怎么叫独立主格呢~

emilyly

看了这么多解释，果然LZ的解释靠谱啊~这里的主语从句总是看着让人不舒服。

这道题根据句意无奈之举选个有主语从句的选项，是不是有形式主语的情况就不选B了呀？这么长个主语放在那儿，选的那会真忐忑~

kkfrancais

namely的意思是“that is to say”，这里应该是一个平行结

构,that....namely that...

TerraceHo

平行结构？？什么和什么平行？