The plural morpheme "-s" is pronounced as /z/ in the f

The plural morpheme "-s" is pronounced as /z/ in the following words EXCEPT______.
A、beds
B、bags
C、cheats
D、bottles
【正确答案】：C
【题目解析】：本题考查第三章词素变体的基本内容，-s在/t, p, k/后面读/s/,在/d,b,j,l/后面读/z/,因而选择C项 cheats。