请教GWD31-5-Q31，多谢！

SGDinosaur

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.

1. 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
2. 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
3. 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
4. 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
5. 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

答案选的是B，第一次看到这种把that放在句首的结构，不太明白，谁能帮忙分析一下？谢谢！

[此贴子已经被作者于2009/8/6 21:51:35编辑过]

lijundkj

我也不清楚这题 盼高人~~ 顶

songer_xj

That some fraternal twins resemble each other greatly while others look quite dissimilar （主语）highlights an interesting and often overlooked feature of fraternal-twin pairs, namely that they vary considerably

That...highlights an ..., namely that ....vary 平行结构。