OG SC No.46 ?

tyou

the  correct answer for No.46  is E,  but is Do missing before or after `than`in this sentence ?

a study commissioned by the department of agriculture showed that if calves exercise and asociated with other calves, they will require less medication and gain weight quicker than do those raised in confinement.

E. associate with other calves, they require less medication adn gain weight more quickly than      


Thanks

hexin

在动作的比较中加'do'固然更好，但是如果没有加助动词，也不能只根据这个判定该答案错。话说白了，GMAT关键是在答案中的比较。