请教 OG 11 紫 39

angela7258

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 claves, 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

在OG11 (yellow) 57 中解释，if x happen, y would..., 条件从句，为什么这里，就不成为条件从句用would呢？

多谢高人指点。

angela7258

thanks for sharing

iamyaoyao

我也问过这个问题.这个结构不是严格要求的,只有一点规定是if从句里一定不能用将来时