帮忙解答万分感谢

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

A. the fact of 错 应该为 the fact that...

B. 没有谓语

E. Because....,this fact...从意思上看好像没有因果关系；they 指代不清

答案似乎在C和D之间

it要指代前面整句话，C中单独出现会没有指代对象

所以我选D

it is a fact 就表明it是在指代前面整句，而不会有歧义了

请LZ给出答案 以解心头之痒

不好意思 自己找到答案了

C D 都错 因为with 引导的是独立主格结构 不能用it指代

B的谓语highlights，句首的that指代整个独立主格结构做句子主语

不过，我仍然有问题：

第二个that修饰feature,与第一that指代不同，却出现在一个句子中。这种现象很少见；

而且they本来是指代twins，但也有可能指代others，不是很清晰

原句：

The fact that some fraternal twin pairs look quite different, while others look quite similar, highlights a very interesting, often overlooked, feature of fraternal twins, namely that they vary on a "spectrum" of genetic relatedness.

我也觉得B有问题，开始也选了D

我觉得B的they可能指代twins 或者others啊

D我觉得it可不可能做形式主语，但我又找不到真正的主语在哪

好好一个句子，让GMAC东改西凑的，  居心叵测啊

美国法律那么健全，等兄弟们去了 告他个篡改语言习惯的民事责任！赔我的脑细胞！

这里的That………. namely that平行所以they并不会产生歧义..

嗯 这样看来更清楚了 多谢前辈