Millie and Kitty are good friends, they often _________ each other _________study.
A:helping; with
B:help; to
C:helping; to
D:help; with
①审查阅读。____
②帝王居住的高大豪华的建筑物。____
③摆放的东西。____
④形容两眼半睁半闭,昏昏欲睡的样子。____
⑤询问;征求意见。____
⑥大致看一下,泛泛地阅读。____