than比较的用法

dct2019

向各位大佬一道请教prep上的比较题

Laboratory rats and mice live up to 40percent longer than usual when fed a diet of at least 30 percent fewercalories than that which they would normally eat, but that otherwisecontains all necessary vitamins and nutrients.

A of at least 30 percent fewer caloriesthan that which they would normally eat, but that otherwise

B  withat least 30 percent fewer calories than what they would normally eat thoughotherwise it

C  thathas at least 30 percent fewer of the calories that they would normally eat, butotherwise it

D  thathas at least 30 percent fewer calories than they would normally eat but thatotherwise

E  thathas at least 30 percent fewer calories than that which they would normally eat,though that otherwise

答案是D
我不太懂得是这里D选项

thathas at least 30 percent fewer calories than they would normally eat里的they would normally eat是什么用法，好像

根据语义我们可以推测这是把calories进行比较，当他们被投喂的diet所包含的calories比他们平时吃的calories 低40%，可是看不到比较的右半部分they would normally eat有calories的意思

是不是我理解错了

momoyi

意思是这样理解。
但比较对象你没有找准。
我们这里比较的是主语diet，而不是在比较calories。

the diet that has at least 30 percent fewer calories than (the diet) they would normally eat

这里有个比较省略，所以让你觉得看不到有calories的意思

dct2019

momoyi 发表于 2019-10-15 19:26
意思是这样理解。
但比较对象你没有找准。
我们这里比较的是主语diet，而不是在比较calories。

好滴！谢谢你的回答！！！
我还有一个不太懂得地方，E选项里的that which为什么是错的呀，我不是太懂这里

momoyi

dct2019 发表于 2019-10-15 19:39
好滴！谢谢你的回答！！！
我还有一个不太懂得地方，E选项里的that which为什么是错的呀，我不是太懂这里 ...

which的用法来看：GMAT里 which做非限定修饰，那么which前面得加逗号。
这里直接修饰that，就不对了。

修饰的语法来看： which they would normally eat
which引导定语从句they would normally eat修饰that
which做的是eat的宾语，which/that做从句中的宾语一般都省掉。那么按照GMAT简明的标准，这个which就更得省掉
按照比较的原则：同样的主语比较，后一个主语得省掉，去掉了that
因此that which就都省掉了。

这就是that which不对的原因
而D就是省略后的样子

dct2019

momoyi 发表于 2019-10-15 20:10
which的用法来看：GMAT里 which做非限定修饰，那么which前面得加逗号。
这里直接修饰that，就不对了。

感谢！！！！我一直都搞不懂这里！！！！