OG12 Verbal 38, 划线部分可以用将来时吗

thelilyonly

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略
B associated with other calves, they require less medication and gain weight quicker than
C. associate with ther 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

OG 上对A的解释有这么一段：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: exercise……associate……require……gain weight

这题选对了，对答案也没有异议。不过看了解释，疑惑就来了。
1，will 句子中平行并列的形式是怎样的？ A will do and do 还是 A will do and will do
2, 把A中associated换成associate是否就正确了呢？

DesmondWang

同意楼上，另外补充一点，gain weight是个动作，所以不能用形容词性质的quicker来修饰，而是要用more quickly

kiwifoodtown

提醒lz和LS注意，will require less 。。。。than do比较结构前后时态不一致，所以不是associated变成associate就能改正确的。

zxppx

我看到这题的第一感觉也是：if X happens, Y will happen.
但是没有一个答案是这样的，包括A选项。因为A选项中的will require and gain,即使是把gain前面的will 省略了，但是associated的时态是错误的。
manhattan中有提到：
as far as the "if X happens then Y happens" construction:

this is a little different, because the "if" and "then" parts are SIMULTANEOUS in this context.

in other words, "the calves exercise and associate" is an ONGOING thing. also, "they require less medication" is an ONGOING thing.
since both of these things are taking place at the same time, it would be illogical to place them in different tenses.
不过很少看到这种用法。就是E选项。
此外，我们不需要去修改OG的答案，因为这样是没有意义的。只需要在5个选项中选一个最合适的。但是，我觉得，如果把A选项中的associated变成associate，应该也是正确答案。欢迎指教！