They aren'______ (I) books. They're ______ (Lily and Lucy).用所给单词的适当形式填空.

问题描述:

They aren'______ (I) books. They're ______ (Lily and Lucy).
用所给单词的适当形式填空.

my
Lily and Lucy's

my
Lily and Lucy's

my,Lily's and Lucy's

my Lily and Lucy's