请问12-year old/ 12-years-old/ 12-year-old/ 12 years old这四项有什么

请问12-year old/ 12-years-old/ 12-year-old/ 12 years old这四项有什么 “-year-old” “years old” 为什么12-year-old=12 years old _____ you 12 years old last year? yes, I _____ 13 years old 11-year-old和11 years old有什么区别 three-year-old 和 three years old 有什么区别 three -year-old 和 three years old有什么区别? Saran is 12 years(old,older).She is one year I _____(be)12 years old last year. My this year 12 years old怎么读 year-old和years old的区别 year-old与years old的区别