[QUOTE]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
这道题的主干参看黄色突出的部分,第一个that引导主语从句,第二个that对应于第一个that。而some fraternal twins resemble each other greatly while others look quite dissimilar,这里的look对应于resemble,都是动词,中间意思转折用了while;一些孪生子彼此极其相像而另外一些看起来十分不同。