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

Thank you!

请问这题的答案B中

namely是不是作插入语 that 跟features作同位语

谢谢

namely = that is to say 也即

我个人认为属于那种同位说明的类型

stoneren, 请问namely that 是不是做feature的同位语

谢谢

我想请问A，除了NAMELY+N/THAT而不能+句子这个错误以外

那个the fact of+长长的一个带限定词的名词算不算错呢？？？

对于namely considerable variation 和 namely that they vary considerably 的区别还是不太理解：楼上说namly 的意思是说it is to say,所以后面要接从句，可看看下面这倒题：

GWD-1-Q30:

The ancient Anasazi harvested such native desert vegetation as the purple-flowered bee plant, what they now commonly call wild spinach in northern Arizona and other parts of the southwestern United States.

1. what they now commonly call



2. a plant that they now commonly call



3. now commonly called



4. and is mow commonly called


5. which it is now commonly called

这也是一个同位补充说明吧，正确答案C也可以看作是 commonly called + Noun;为什么不能在本题中说：namely + Noun呢？或者说，如果将原题改为：commonly named a considerable variation是不是就正确了呢？

这种题应该如何把握呢？