-----(双胞胎的卧室）are very nice.-----(学生们的桌子）are very old.
问题描述：
-----(双胞胎的卧室）are very nice.-----(学生们的桌子）are very old.
答
1 The bedrooms of the twins/The twins' bedrooms
2 Students' desks/tables
/The desks/tables of the students
主语必须是复数名词后面谓语动词是are