Millie and Kitty are good friends they often each other study.A. helping; withB. help; t

问题补充：

Millie and Kitty are good friends, they often each other study.

A. helping; with

B. help; to

C. helping; to

D. help; with

答案：

A. helping; with

B. help; to

C. helping; to

(答案→)D. help; with

解析：句意：Millie和Kitty是好朋友他们经常在学习方面互相帮助。often，经常用于一般现在时。主语是复数，谓语动词用原形。help sb (to)do sth,帮助某人做某事，help sb with sth,帮助某人在某方面。故选D