18 - to- 21- year-olds 为什么old加s
They were children.Four and five-year-olds,为什么old加s
he is 18 years old.为什么year要加S
year olds还是years old?
sixteen year olds 还是sixteen year old?
为什么Six Years Old.中Year要加S呢?
英语九上第三单元为什么是sixteen-year-olds,old不应该用单数吗
sixteen-year-olds可以直接使用,sixteen-year-old不可以直接使用后面要加boy?
six-year-old与six-year-olds的区别
sixteen-year-olds跟sixteen-year-old有什么区别?
fifteen-year-olds和a fifteen-year-old boy
sixteen -year -olds和sixteen -year -old有什么区别
an eight-year-old boy为什么year不加s 这属于什么语法