OG11紫色39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．

A  Associated and will require do not match exercise and gain；the adjective quicker should be the adverb more quickly; do must be omitted．

B  Associated is in the past rather than the present tense；quicker is used in place of the correct more quickly．

C  Required and will gain are not in the present tense；quicker is used in place of the correct more quickly；do must be omitted．

D  Have required and will gain should be in the present tense；do must be omitted．

E  Correct．In this sentence，the verbs are all in the present tense；an adverb correctly modifies the verb phrase；the comparison is logical and grammatically correct．

The correct answer is E．

对于这道题好象答案里把IF...WILL这样的时态排除掉了。请问为什么不能用IF....WILL....这样的时态呢?谁能解释一下什么情况下用IF...WILL呢?

这是虚拟语气把.时态问题可参见语法书