【导学过程】选择
（ ）1. Today is September 10th. It's ________ Day.
A. Teacher B. Teacher's C. Teachers' D. Teacher'
（ ）2. It's June 1st, it's ________ Day.
A. Childrens B. Children's C. Childrens' D. Childrens's
（ ）3. This year, ________ is on May 9th.
A. My mother's brithday B. My mothers' birthday
C. My mothers brithday D. My mothers's brithday
