Prep 破解P60 页有个关于比较省略的问题，求高人指导！

仰望星空的石子

再比如这个句子：According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than (that of) livestock fed on grain and more of a kind of fat thought to be good for cardiac health. 这个句子不对。其在livestock前加上that of…比较的对象是animals has less fat和that，that指代fat，（此处不太明白，此处的比较对象可以理解为fat和that (that 指代fat）进行的比较啊，所以fat应该是可以和that of livestock作比较的吧）而事实上比较的应该是wild animals和livestock的属性，即拥有fat的多少（注意不是比较fat的属性），所以than后面也应该用平行的句式，即主谓宾形式，正确句子为：According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than livestock fed on grain and more of a kind of fat thought to be good for cardiac health. 不过在此省略了相同的谓语和宾语（因为不会有wild animals have livestock的歧义，只要逻辑上基本成立，GMAT并不认为所有没有补出谓语动词的形式都是”ambiguities”的）。（这个句子不对的另外一个证据： more of a kind of fat 后面省略了(than…)，而省略的部分应该和less total fat than后面的词句是一致的，这样才能省略?逻辑上看省略的必须是livestock，而不能是that of livestock，因此less total fat than后面跟的也应该是livestock。）

这句话是不是可以这样认为如果前面是that of livestock 则后面的 more of a kind of fat 后面省略是也应该是 than that of livestock ，就容易造成前后两个that指代不清的问题。而如果前后均是livestock does，主谓省略，则不会出现指代不清的问题了。实在想不明白了。求高人指导！跪谢！