OG10语法268题中补足谓语的问题（冰天雪地寒风赤裸求助）

chengzi1

A study commissioned by the Department of Agricul­ture showed that if calves exercise and associated with other calves, they will require less medication and gain weight quicker than do those raised in confinement.

A. associated with other calves, they will require less medication and gain weight quicker than do
B. associated with other calves, they require less medication and gain weight quicker than
C. associate with other calves, they required less medication and will gain weight quicker than do
D. associate with other calves, they have required less medication and will gain weight more quickly than do
E. associate with other calves, they require less medication and gain weight more quickly than


答案：E

请问为什么E选项中不用补谓语动词do？？不是说A do sth than B do 的吗？这里我的理解是they require medication and gain weight，than后面不是应该补do 对应require 和gain吗？



冰天雪地寒风凛冽赤身裸体郊外跪求牛人解释。

P.S. 我发现在GMAT中can和could，will 和would 的使用区别不大，请问是这样的吗？

chengzi1

刚刚马上在大全中找到答案：
gemj:这个句子之所以不补出，而且THAN的前面虽然有宾语，但是双重动宾结构。从语法上、逻辑上都不会产生those raised in confinement与weight或medication相比较的嫌疑。当然，就这个例子来说，如果补出，并不算多余。这才是补与不补均可的情况吧。