请教一道 比较题

39. 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

Verb form + Diction

The first and last verbs in the series of verbs that describe the calves are in the present tense, so the two in the middle should be as well：the Calves exercise．．．associate．．．require．．．gain weight．Adverbs，not adjectives, describe how an action is carried out．These calves gain weight more quickly，not quicker, than other calves．The comparison is between calves and those (referring to another set of calves)；the verb do ungrammatically interrupts the comparison and should be eliminated．

按理主语比较且than前有宾语的应该补出助动词的，但按照OG这里的解释，助动词在这里反而不对，应该省去。觉得与比较的一般规则不太一样，请哪位NN解释一下，谢谢！

Choice E, the best answer, uses the adverbial phrase more quickly than to modify the verb phrase gain weight. In A, B, and C, quicker than is incorrect because an adjective should not be used to modify a verb phrase. E is also the only choice with consistent verb tenses. The first verb in the clauses introduced by showed that is exercise. A and B incorrectly compound that present tense verb with a past tense verb, associated. C and D correctly use associate, but C follows with the past tense required and D with the present perfect have required. Both C and D incorrectly conclude with the future tense will gain.

我这是OG10的解释,不知道你说的OG解释是什么版本的

我觉得这里可省可不省,在不影响歧异的时候最好省掉