year olds还是years old?

year olds还是years old? sixteen year olds 还是sixteen year old? 16-years-old和16-year-olds的区别 Sixteen-year-olds什么词性 sixteen years old 什么词性 16岁 英语 怎么说是 sixteen-years-old还是sixteen-year-olds?还有 不加一横的？越来越混乱了 six years old 和 six- year- old 和 six- year- olds的区别如题 16-year-old和16-year-olds和16 years old有什么区别? sixteen-years-old与sixteen years old有什么区别sixteen year olds与sixteen-year-old都是什么时候用 my new friend is a ( )boy.A soxteen-years-old Bsoxteen-years-olds Csixteen-year-oldmy new friend is a ( )boy.A soxteen-years-old Bsoxteen-years-olds Csixteen-year-old Dsixteen-year-olds 请问怎么用比如：ten year old 我见过有些选择题是这样的 Ten--years--old Ten--years--olds Ten--year--olds Ten--year--old Ten years old Ten years olds Ten year olds Ten year old我见过有些英语是这样的,请问这个 Ten year o ___should not be allowed to go out at night.a.Twelve-years-old b.Twelve-year-olds c.Twelve-year-old d.Twelve-years-olds [ ] should not be allowed to drink wineA ten-year- old B ten-years-old C ten-year -olds D ten-years-olds ____should not be alowed to go out at night.A.Twelve-years old B.Twelve-year-olds C.Twelve year old D.Twelve years olds选什么 为什么? 初三英语语法题Do you think () should be allowed to drive?A.sixteen-year-old.B.seventeen-year-olds.C.fifteen-year-old.D.eighteen-years-olds 60-year-olds为什么Old会加上一个S?60-year-olds为什么Old会加上一个S,它和60 years old有什么区别? I think ( ) should not be allowed to drive.A sixteen years old B sixteen-year-old C sixteen-year-olds I think ____should not drive anywhereA.sixteen-year-old B.sixteen-years-old C.sixteen-year-olds为什么 请问X-year-old和X years old 的区分和具体用法?还有 X－year－olds