11 year old和11-year-old有什么区别

11 year old和11-year-old有什么区别 11-year-old和11 years old有什么区别 sixteen -year -olds和sixteen -year -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? four-year-old和four year old有什么不同 16-year-old和16-year-olds和16 years old有什么区别? sixteen year old、sixteen-year-olds、sixteen-year-old有什么区别 sixteen-year-olds跟sixteen-year-old有什么区别? year-old和years old的区别 six-year-old boy和six years old boy 有什么区别?一样么?为什么? five-year=old和five years old用法有什么区别啊