问题补充：
They are bedrooms.
A. Lily and Lucy’s
B. Lily’s and Lucy
C. Lily and Lucy
D. Lily’s and Lucy’s
答案：
A. Lily and Lucy’s
B. Lily’s and Lucy
C. Lily and Lucy
(答案→)D. Lily’s and Lucy’s
解析：bedrooms前面应填所有格的形式
故排除BC
A. Lily and Lucy’s是指Lily and Lucy共有的，对象为一个
D. Lily’s and Lucy’s是指Lily and Lucy各自的,对象不止一个
而 bedrooms为复数
故选D
