一道sc平行的问题，求大神解答~~~

Whistle要考gmat

Among lower-paid workers, union members are less likely thannonunion members to be enrolled in lower-end insurance plans imposingstricter limits on medical services and requiring doctors to see more patients,and spend less time with each.（D）

窗体顶端

·        A  imposing   stricter limits on medical services and requiring doctors to see more patients, and spend

·        B  imposing  stricter limits on medical services, requiring doctors to see more patients, and spending  

·        C  that impose   stricter limits on medical services, require  doctors to see more patients, and spend  

·        D  that impose   stricter limits on medical services and require doctors to see more patients,spending  

·        E  that impose stricter limits on medical services,requiring doctors to see more patients and spending

答案选D...想问一下为什么不能选C？不能把spend 看作是 to see 的平行吗？记得看过哪个大神写的说平行比较中固定搭配的to 可以省去，那这里require sb to do sth  and to spend 后面的 to 不能省去吗？？谢谢~~~