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