问题补充：
单选题Jimwaslatefortwoclassesthismorning.Hesaidthatheforgotbothofthe______.A.rooms numberB.room numberC.room’s numbersD.room numbers
答案：
D解析room 为无生命名词，不用 room’s 这样的所有格形式，在此可直接用名词作定语。类似地，下面一题要选B，也是一样的道理（名词作定语通常用单数不用复数）：The boy was very happy that his mother bought him a new pair of shoes at a ______ yesterday.A. shoes shop B. shoe shop C. shoes’s shop D. shoe’s
