帮助，885 section A 23！

不是很明白help的用法，help （to）需要省略吗？

23.   Ideally, the professional career diplomat should help in the ongoing maintenance of an effective American foreign policy despite changes in administration.

(A) in the ongoing maintenance of

(B) in the maintaining of

(C) maintain

(D) to maintain and continue（C）

(E) the maintenance of

to 是可以省略的

help somebody (to) do something

I helped her to carry her cases up the stairs.

She helped him choose some new clothes.

herbal products that help you to relax and sleep

help (to) do something

She was coming to help clean the machines.

大多数情况下to都省略。

D. maintain和continue这里语义重复