OG 12-38

mliu9

正确句子： a study commisioned by the department of agriculture showed that if calves exercise and associate with other calves, they require less medication and gain weight more quickly than those raised in confinement.

对答案没有太多疑问
但是OG的对动词补出的解释我很迷茫，the verb do ungrammatically interrupts the comparison and should be eliminated.
其他选项有动词do的补出：gain weighe more quickly than do those raised....

我们不是一直强调在主谓宾结构中，主语比较时要尽量补出动词么。。为什么OG上却说不要do呢？

michaelmay17

我的理解是这样的，例如 i eat apples more quickly than you do .这个句子如果do省略了，就是 i eat apples more quickly than you 会造成歧义，此时do补出，意思就是do的补出是为了避免逻辑歧义，所以这才是根本问题所在，而不是迷恋任何所谓的规则，规则常有例外~