32.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 the key:E 比较考点——do 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。

不是很理解上面的解释，请各位大牛帮忙解释下，谢谢！

就是说，than前后的比较对象一定要一致（不论是语法上，还是逻辑合理性上），具有可比性

语法上：

先举个简单例子：I eat more apples than you (do).

如果不加do,那么语法上you和apples并列，意思变成：我吃你，比吃的苹果多；如果加上do，那么语法上you和I并列，do和eat并列，意思是：我吃的苹果比你吃的苹果多。

而本题中，因为than前面是两个动宾结构，即时不补出do，也不会发生歧义，因为those raised in confinement不可能既做require的宾语，又做gain的宾语；因为这两个动词要求的宾语在性质上很不一样，一个是药品，一个是体重。

require less medication and gain weight more quickly than those raised in confinement

这就排除了一种可能，从而只能与两个动病结构的主语they在语法上并列

逻辑上：

就是意思上，很显然，those raised in confinement不会与medication或者weight并列比较，意思上说不过去的