only four year old意思

only four year old意思 only four years old的意思 four-year-old和four year old有什么不同 my father is---------- (four) year old 关于four－year－old He is only four years old.是什么意思? a four-year-old boy可以说成a four-year old boy he is only one year old是什么意思 请问:是a four years old boy?还是a four year old boy?正确 four-year-old和middle-aged 杠表示是什么? Jack is only four years old.(对划线部分提问) only four so ye什么意思?